Minggu, 30 Mei 2010

How to Know When a Rod or Main Bearing Is Bad

How to Know When a Rod or Main Bearing Is Bad

The rod and the main bearings are located in an automobile engine. These bearing are used to protect the crankshaft, or connecting rod. The bearings help the shaft to spin freely inside the engine. When these bearing go bad, glaring signs will let you know they are bad or heading in that direction. One glaring sign is a noise that sounds like knocking. Faulty engine bearings need to be replaced as soon as they go bad.

Instructions

    1

    Insert the vehicle's key into the ignition and start the car.

    2

    Roll down the window to give you a better chance at hearing any noises. Some newer cars have almost no engine noise inside the passenger area, and it may be difficult to hear any engine noises without the window down.

    3

    Listen for any kind of knocking noise coming from the front end of the vehicle. If there are sounds, and they continue once the engine is running, it may be a faulty main bearing. A low oil pressure warning light may accompany a faulty main bearing.

    4

    Listen for a knocking noise that sounds more like striking tin or aluminum and increases as the vehicle accelerates. It is probably a faulty rod bearing.

Sabtu, 29 Mei 2010

How to Find the Compression Stroke

How to Find the Compression Stroke

Obtaining the compression ratio of an engine is a vital part of any rebuild but thankfully, finding the compression stroke is the easiest part of the ratio calculation. It just entails that you rotate the camshaft of an engine so that the cylinder heads rotate up and down within their cylinders. You measure the difference between the full extension and full compression to obtain the stroke of the cylinder head. This can then be used for your ratio calculation.

Instructions

    1

    Remove the head bolts from the top of the engine with a wrench; there will be at least four bolts but the exact number depends on the model of engine. You will not be able to move the engine without removing all the bolts.

    2

    Lift the head off the engine block. The head can be lifted by hand on most four- through eight-cylinder cars, but if you have an engine with ten or more cylinders you will need an assistant. Use care when removing the engine head as it can be quite heavy and it can snag on wires or other connections in the engine bay.

    3

    Locate a cylinder to measure. It does not have to be at full extension or compression. Locate the camshaft at the front of the engine. It will be hooked up to the serpentine belt. Rotate the camshaft by hand until the cylinder you are measuring is at full compression. At this point, mark the inner wall of the cylinder with a grease pen. Rotate the cylinder to full extension and mark that level with a grease pen.

    4

    Rotate back to full compression again and use the ruler to measure the distance between the two levels. Repeat this process until you have measured the compression stroke on every cylinder. You must measure every cylinder because of the possibility of damage on the cylinders or a warped camshaft.

    5

    Reattach the engine head and re-secure the anchor bolts.

Code P0300 for a 1996 4.3L Chevy Blazer

On-board diagnostics code p0300 on a 1996 Chevy Blazer equipped with a 4.3-liter engine means the computer has detected multiple random misfires across one or more cylinders during engine operation. Code p0300 can be caused by one or more things, including a faulty component or a lack of maintenance.

Spark Plugs and Wires

    If the spark plugs have not been serviced recently, now would be a good time to change your plugs and wires. Over time, the spark plugs will become worn and begin to fail, causing the engine cylinders to misfire. Another common reason for cylinder misfiring is damaged plug wires. If the plug wires are not transferring enough current from the coil, the spark plug will not fire correctly and cause a misfire.

Ignition Control Module and Coils

    The 1996 Chevy Blazer has a distributor-less ignition system, which means it uses coil packs to distribute current to each spark plug. This vehicle uses three coil packs (two cylinders each) that are mounted onto, and controlled by, an ignition control module. If every cylinder is misfiring, it is possible the ignition control module has failed. If some cylinders are firing properly and some are misfiring, then it is possible that a coil pack has failed and needs to be replaced.

Air Delivery

    If the ignition components are working properly, it's possible a misfire is being caused by too much air entering into the combustion chamber. The 4.3-liter engine has several vacuum lines that can break or accidentally be disconnected. A vacuum leak allows air into the intake manifold, which offsets the air-to-fuel ratio. Inspect all vacuum lines and replace any damaged or leaking vacuum line as necessary.

Fuel Delivery

    If there is a lack of fuel making it into the combustion chamber, there will be too much air and not enough fuel, causing a misfire or in some cases a no-fire on that cylinder. Lack of fuel can be caused by clogged fuel injectors, a dirty fuel filter, fuel leak or a weak fuel pump. Inspect the fuel lines for leaks and check the fuel pressure., which should run between 60 to 66 psi. If the fuel pressure is low, replace the fuel filter, especially if it hasn't been serviced in a while. If the fuel pressure doesn't increase, the fuel pump may be faulty.

Less Common Causes

    In some cases, a faulty oxygen sensor can relay faulty information to the computer, causing the computer to incorrectly adjust the air-to-fuel mixture. If the crank position sensor has become faulty, the computer could initiate spark at the wrong time in the compression stroke of each cylinder, causing the cylinders to misfire. In rare cases, the vehicle computer or ECM has become faulty and is relaying bad information to vital engine components; but this will often display many error codes and affect engine performance.

How Do I Troubleshoot a 1986 300ZX That Won't Start?

How Do I Troubleshoot a 1986 300ZX That Won't Start?

The 1986 Nissan 300ZX is a two-door sports car built and marketed by the Nissan Motor Corporation of Japan. The 300ZX replaced the 280ZX, which saw an increase in engine displacement over the 280ZX. The 300ZX was eventually replaced by the 350ZX. For 1986 the body was slightly restyled, adding side skirts and fender flares to improve the aerodynamics of the car. The 1986 model saw an increase in tire size (16 inches). If your 1986 300ZX won't start there are a few things you can to do troubleshoot it at home.

Instructions

    1

    Insert the key into the ignition and turn it to the accessory position. Observe the fuel gauge and confirm you have gas in the tank before you try to start your 300ZX.

    2

    Turn the key to the start position and try to start the 300ZX. Listen to the noises coming from the car, as they will help you in determining the problem. If you hear a clicking noise coming from engine compartment, that is a good indication the starter motor may need to be replaced.

    3

    Remove the key from the ignition and pull the lever to open the engine hood on your 300ZX. Inspect the battery and observe if there is corrosion built up on the connections. Corrosion can weaken the connection and restrict the amount of power transferred to the starter motor. Clean the battery connections with a wire brush to remove corrosion. Mix 1 cup water and 1 tbsp. of baking soda. Pour a small amount of the mixture on the battery connections to loosen excessive corrosion and then scrub off with a wire brush.

    4

    Connect a battery meter to your 300ZX battery. Connect the red clip of the meter to the positive post on the car battery. Connect the black clip of the meter to the negative post on the battery. If the meter reads 10 volts or less, try "jumpstarting" or "boosting" your 300ZX to get it started. Connect emergency jump start cables to your battery. Connect the other end of the jump start cables to a friend's car that is turned off. Be sure the same cable is connected to the negative post on your 300ZX and to the negative post on your friend's car. Repeat the process with the positive cable. Have your friend start their car, then start your car.

    5

    Disconnect the spark plug wires from the spark plugs and remove them with a spark plug wrench. Clean the black carbon off the bottom of the spark plugs, or replace with new ones. Reinstall the spark plugs and reconnect the spark plug wires.

Jumat, 28 Mei 2010

Do Pulsating Brakes Indicate Imminent Rotor Failure?

Do Pulsating Brakes Indicate Imminent Rotor Failure?

A pulsating sensation when braking signifies a need for maintenance within you vehicle's brake system. However, a slight degree of brake rotor failure has already occurred by the time you sense these pulsations. Brake rotors can warp under the accumulation of excess heat that that can be generated through various causes. The heat creates lateral distortion, or run-out, which is measured in minute increments. The tolerances specified by vehicle and parts manufacturers are extremely tight, with zero run-out as the desired target. Great care is taken to squarely mount a brake rotor onto a lathe spindle to ensure a truly flat cut during the machining process.

Round and Round

    Brake rotors begin their service life as close to perfectly flat as modern machining methods allow. New rotors are often stored flat on the shelf, rather than on edge, to prevent imperfections. The level surface of the friction area permits full, even contact with the brake pads for uninterrupted stopping power. Hard spots can be burned into the braking surface of a rotor from extreme heat loads, like those generated by panic-stops and overloading the vehicle with cargo. The same reasons can cause the rotors to distor or warp slightly, making the brakes seem to grab and release multiple times across a short distance. Warped rotors can be trued on a brake lathe, provided that they are not worn too thin. Charred hard spots resist machining efforts and require the afflicted rotors to be replaced.

Big Squeeze

    As the brake pedal is applied, the caliper pistons push the brake pads into firm contact with the rotor. Lateral motions of a warped rotor force the piston back into the caliper bore repeatedly. The pistons are hydraulically linked to the brake master cylinder, and eventually, the pedal. The pulses sensed at the pedal can be exaggerated by the surging experienced as the vehicle stops. Extensive stop-and-go driving, or continual harsh applications, can create rotor distortions. Erroneous driving practices are often to blame when brake rotors require frequent service.

Heat Mizer

    Keeping one foot on the brake pedal while traveling is known as "riding the brakes". This bad habit may grant a false sense of security to tailgating drivers, but no real benefits are had with this misguided practice. Even the slightest pressure on the brake pedal forces the pads into firm contact with the spinning discs. Heat generated by the increased friction not only warps the rotors, but also burns a glaze onto the pads. Stopping distances are extended when the pads are distressed, and the fractions of a second saved by maintaining brake pedal contact are more than discounted by the reduced stopping abilities. Allowing proper following distance between vehicles reduces the need for short stops and riding the brakes. Keeping the heat down ensures brake pad and rotor longevity and optimizes system performance.

Free and Easy

    Along with fine-tuning some driving skills, some basic maintenance and attention to detail may forestall undue brake system wear and tear. Occasional brake inspections might prevent any particular discrepancy from affecting associated parts and system performance. Most repair shops offer this service at no charge, in hopes of providing needed repairs or maintenance procedures. Vehicles with drum brakes on the rear axle may benefit from a cleaning and adjusting of the rear shoes. This procedure also rids the assembly of friction material dust that collects inside the drum. The front brakes last longer if the rear brakes are doing their job. A thorough inspection may reveal a binding or rusty parking brake cable that could keep the brakes applied. This matter should be investigated whenever the parking brake pedal or lever fails to retract completely. Heed the vehicle manufacturer's recommendations regarding weight loads and placements. Remember to increase following distances any time your vehicle is weighted down with all the people and goodies you might pack for an outing. Arriving safely should always be the main objective.

How to Troubleshoot Code P1410 on a GMC Envoy

How to Troubleshoot Code P1410 on a GMC Envoy

The GMC Envoy, and it's cousin the Chevy Trailblazer, are General Motors entries into the mid-sized SUV market. Replacing the GMC Jimmy and Chevy Blazer in 2002, these vehicles were equipped with an OBD II electronic engine management system that featured standardized diagnostic trouble codes (DTC) that met federally mandated protocols. DTC P1410 is related to a fault in the vehicle's fuel tank pressure sensor that monitors the pressure of fuel vapors that build in the fuel tank as the gasoline evaporates.

Instructions

    1

    Park the Envoy on level ground. Jam wheel chocks securely against the front tires. Lift the rear of the SUV using a floor jack under the center of the rear differential. Place jack stands under the frame on both sides. Remove the gas cap.

    2

    Remove the 15 mm bolts that secure the fuel tank straps to the frame and allow the tank to hang down. Unplug the three-wire electrical connector from the sensor located on top of the fuel pump assembly.

    3

    Set the digital volt/ohm meter to read volts d/c. Turn the ignition key to the "RUN" position. Test for a 5 volt reference signal by touching the positive meter lead (red) to the terminals inside the electrical connector as you hold the negative lead (black) against the frame. The voltage should be nearly 5 volts on one of the three terminals. Replace the fuse or repair the wiring harness if no 5 volt reference voltage is present.

    4

    Set the meter to read "OHMS". Test for ground by touching the red meter lead to the middle terminal while holding the negative lead against the frame. Resistance should be present. If 0 ohms or infinite ohms is indicated, repair the ground.

    5

    Plug the sensor connector back into the sensor and touch the positive lead to the remaining wire while holding the negative lead against the frame. Voltage should be between one volt and four volts. Replace the sensor if it measures less than one volt or more than 4 volts.

Kamis, 27 Mei 2010

How to Troubleshoot a 1998 Plymouth Neon

How to Troubleshoot a 1998 Plymouth Neon

One of the most common problems to troubleshoot in vehicles, including the 1998 Plymouth Neon, is figuring out why it won't start. For an internal combustion engine to start, it requires the starter motor to get the engine turning, the correct amount of fuel, and enough air and spark to ignite that fuel. If any of these elements are not present, then the engine in your 1998 Dodge Neon will likely not start.

Instructions

    1

    Insert the key into the ignition and turn the key to turn the engine on. Listen for any sounds coming from the engine compartment. A clicking sound when you try to start the car is an indication that the starter motor on you 1998 Plymouth Neon will need to be replaced.

    2

    If the engine is not turning at all, there is a good possibility that the battery needs to be jump started or replaced. Take the key out of the ignition and pull the engine compartment lever to release the latch on the engine hood.

    3

    Lift the engine hood, locate the battery. Connect a battery meter to the battery and look on the meter and read the volts remaining in the battery. If the the reading on the voltmeter is 11 volts or less, then the battery will need to be charged, jump started or replaced.

    4

    If the engine is turning but not starting, remove the key from the ignition. Open the engine hood and disconnect the spark plug wires. Remove the old spark plugs using a spark plug wrench. Inspect the ceramic portion of the spark plug for cracks. If cracked replace the old spark plugs with new ones. If they are not cracked, clean the carbon off of the bottom of the sparkplug. Replace the spark plug, reconnect the spark plug wires and try to start the car again.

How to Diagnose Car Faults

How to Diagnose Car Faults

A car's dashboard features a few trouble indicators. There is the standard check engine light, as well as lights for ABS brakes, tire pressure monitoring and other systems. Each of these systems runs tests, and once a problem develops, the system generates a fault code and triggers a warning light. Retrieving fault codes is simple. However, you will need the proper scanner. Most economically priced scanners are dedicated to one system. An On-Board Diagnostic scanner cannot read TPMS fault codes. Some scanners are more integrated, but the increased capability raises the retail price.

Instructions

    1

    Climb into your driver's seat and start your vehicle's engine. You cannot simply start the electrical system in some vehicles to see the active lights indicating trouble.

    2

    Look at your dashboard and take note of which lights indicating trouble are active. This will dictate which type of diagnostic scanner you will need.

    3

    Drive to an auto parts store and shop for a scanner. If you want more use for your money, you will need a scanner that at least understands OBD-II coding. This covers more areas within your vehicle, and by that reasoning, you will get more use out of it. Also, it will save money in the long run. Some stores and garages may be willing to lend you their scanner for use, but many will not be and will charge diagnostic fees.

    4

    Once you reach your home garage, turn the vehicle off. Reach under your dashboard and find your vehicle's data link connection. This is a diagnostic outlet, and it serves as a gateway into your vehicle's diagnostic system. It accommodates a wide 16-pinned plug, and it should either be directly underneath or by the side of the steering column. OBD-II, ABS and TPMS scanners all hook up into this outlet. Before using the scanner, consult your user's manual for exact instructions on what to do. There are slight variations in the process, as different brands of scanners work slightly differently. The buttons are not all in the same configuration. The process, though, is similar in intent.

    5

    Plug your diagnostic scanner into the data link connection.

    6

    Start your vehicle's engine. The next couple of steps depend on the exact scanner you have purchased. Either the scanner will switch itself on, or you may have to key the power button. Once on, some scanners will immediately retrieve the code, and others need a "Read" command entered.

    7

    Read the trouble codes that appear on your screen and consult your manual for their meaning. This will pinpoint the problems in your vehicle. Some codes, especially with OBD-II, are specific to manufacturers. If your manual does not contain the trouble code you are looking for, you will have to go online and find them. This is not especially hard to do (see Resource section). It will help you decide whether you can attempt the repair yourself or whether you need to drive the car to a mechanic.

Brake Drag Causes

Brake Drag Causes

Brake drag is caused by any number of problems that interfere with the proper operation of a vehicle's braking system. Brake drag results in warped rotors, premature brake-pad wear and brake failure. One sure sign of brake drag: your car begins to pull in one direction.

Brake Shoe Release

    Brakes will drag if the brake shoes do not release completely. The brake pads remain open around the rotors until the brake pedal is pressed. Then, the calipers engage the brake pads, closing them around the rotor and stopping the vehicle. Brake drag results when the brake pads do not completely release, or if they open after the brake pedal is pressed. This happens if brake fluid is low. Check the brake-fluid level to determine if this is the cause. The brake-fluid reservoir is under the hood, usually on the driver's side.

Jammed Calipers

    Brake calipers open and close the brake shoes around the rotors. Calipers become jammed in the open position due to misalignment or corrosion. (Corrosion buildup occurs when debris get "pinned" in the calipers. This debris stems from brake wear or debris accumulating on underside of the car. The calipers also get misaligned when brake pads are replaced. The brake pads must slide back over the rotors in the same grooves as the brake pads you are replacing.

Hand Brake Sticks

    Brake drag also occurs when the cable running to the parking brake gets stuck. Have a mechanic take a look at this problem. Note: this cable is difficult to access, so have a mechanic take a look to determine if the cable need to be replaced.

Rabu, 26 Mei 2010

Ford Code P0012

The P0012 error code on your Ford indicates a malfunction with the "A" camshaft timing, specifically, it is over-retarded. When the P0012 error code is shown, the check engine light will also be illuminated.

Significance

    Which camshaft is the "A" camshaft varies depending on the vehicle. It can be the intake, front or left camshaft on your Ford. An error in timing with this camshaft will lead to hard starts, poor idling and possibly stalling of the vehicle.

Causes

    An over-retarded camshaft is caused by a non-functioning variable camshaft timing solenoid. In addition to this solenoid being inoperable, this error code on your Ford could be caused by an issue with the variable camshaft timing solenoid wiring, continuous flow of oil to the variable camshaft timing piston chamber, or a valve control solenoid that is stuck open.

Considerations

    It is important to verify that the variable camshaft timing solenoid is not in operation before replacing it. If an obviously stuck solenoid valve is not seen during inspection, allow a Ford dealership or other Ford-specialized mechanic to check the unit. They have access to advanced tools to check and diagnose any problems within the powertrain of your Ford.

What Causes Car Springs to Break?

What Causes Car Springs to Break?

Coil springs, shocks and struts are parts of an automobile's suspension system that both supports the vehicle and provides for a comfortable ride. Several situations and conditions can lead to coils on a vehicle wearing abnormally and breaking. In some situations, coils break as the result of other components failing so drivers are urged to address suspension problems quickly to avoid any serious complications.

Rough Road Conditions

    Coil springs, shocks and struts are designed to withstand rough road conditions but some changes in the roadway can be too much to bear. Large pot holes and sudden changes in road height can contribute to coils breaking. Using a vehicle in an off-road setting that has not been designed for it can also contribute to broken springs since these coils were designed to handle the bumps of an average paved road, not the unpredictability of rocky terrain.

Fluid Leaks

    According to automotive repair website AA1 Car, ripped seals in a vehicle's struts can cause fluid leakage. This leads to more strain being placed on coil springs which can damage them to the point of breaking. Additionally, a decrease in hydraulic pressure can cause springs to contact with other suspension components, brake lines and even exhaust components causing further damage. Vehicles that show increased noise when going over bumps or dips in the road may be experiencing hydraulic fluid leaks.

Wheel Imbalances or Blown Tires

    Wheel imbalances due to misalignment or through damaged tires can cause uneven wear to suspension components which can lead to damage and breakage of coil springs, shocks and struts. Riding on a blown tire puts a vehicle's springs and other suspension components in direct contact with the roadway stressing components beyond normal limits. This is particularly dangerous if multiple coils break as this could seriously damage a vehicle's brakes, steering system and axles.

Selasa, 25 Mei 2010

My '87 Ford F-150 Has No Power Steering

The power steering system on the 1987 Ford F-150 includes the power steering pump and reservoir, steering gear box and power steering pressure lines. The failure of the power steering system will result in the need for added effort into turning the steering wheel and vehicle. When diagnosing the cause of power steering failure, several things should be inspected or checked.

Power Steering Fluid

    Quite often people mistake a power steering failure for low power steering fluid. In most cases, the power steering fluid is like most other fluids in the vehicle and will always maintain about the same level. A small power steering leak, often one that is unnoticeable, will eventually cause the power steering to run dry. Check the power steering reservoir; if the fluid is low, that mostly likely is the cause of the loss of power steering. It is recommended to search over the system to determine the source of the leak and repair the damaged seal before the leak becomes worse.

Power Steering Hoses

    The power steering setup on the 1987 F-150 requires only two hoses, a pressure hose and a return hose. Inspect both hoses, from the power steering pump to the steering gear box, for any holes or other damage. If the pressure hose becomes damaged, the power steering will not function until the hose is replaced. If the return hose is damaged, the power steering may work momentarily until the fluid is evacuated from the system through the damaged area. If either hose shows any external wear or damage, replace the hoses and repair the source of the external wear or damage.

Power Steering Pump

    The power steering pump creates hydraulic pressure required for the power steering to function properly. Before an obvious power steering failure, it is common for there to be a whine coming from the power steering pump. When the bearings wear or seize, the pulley shaft will no longer maintain a perfect axis and will create a metal-on-metal noise. It is a good idea to replace a power steering pump when it starts to whine, as opposed to waiting for a complete failure. The best way to check for bearing failure in the power steering pump is to remove the serpentine belt and try to turn the pulley by hand. If there as resistance or wobble, the power steering pump should be replaced.

Gear Box

    There were three different types of gear boxes in the 1987 F-150. The Koyo, Saginaw and torsion bar gear boxes had their differences, but in the end they all had the same purpose: to hydraulically assist in rotating the tires to the left or right. If the internal components inside any of the three gear boxes are excessively worn or damaged, there will be metal shavings in the power steering fluid. If there are, the gear box must be repaired or replaced immediately or steering capability could be suddenly lost, posing a serious risk to the driver and others on the road.

Symptoms of Engine Bearing Failure

Of all the things that can take your engine out, bearing failure is one of the most insidious. Car-oriented types tend to try to ignore bearing issues, compensating for them by using ever-thicker oil and an eye on the gauges instead of just replacing them as necessary. But bearing wear can have broad-ranging consequences not only to your engine, but to anything bolted to it.

Silver Shavings in the Oil

    A certain amount of silver-like, metal sheen -- actually aluminum dust -- in the oil and on the dipstick is a result of normal bearing wear. But this dust should be just that; a powder fine enough that you cannot make out any individual grain of aluminum. But when bearings as a result of overheating or running out of oil, the bearings' aluminum outer face will typically shave away in fine splinters or ribbons. If you find splinters or ribbons of aluminum stuck to your dipstick or in the oil during an oil change, then you've got a bearing either gone or on its way out. A good mechanic will always cut the top off of his oil filter after each oil change to check the filter media for early signs of excess aluminum dust and shavings.

Copper Sheen in the Oil

    Many bearings use three layers; a soft aluminum outer layer, a layer of copper in the middle and a steel backing plate. Such tri-metal bearings use copper, which is a softer but slicker metal than aluminum, to give the owner a last line of defense before the bearing wears down to the steel or fails completely. The copper layer will typically last one or two thousand miles, giving you an opportunity to detect imminent bearing failure before it kills your motor. Once you bearing gets down to the copper layer, the bearing will send out a red flag in the form of copper dust in the oil. If you see a ceppory sheen on your dipstick, inside the valve cover or in the oil, then you've got a bearing on the verge of failure.

Loss of Oil Pressure

    Your oil pump flows a certain amount of fluid: say 20 gallons per minute. If you've got 20 little pressure leaks in the engine -- leaks like the hydraulic lifters, the rocker arms and the gaps between your engine bearings -- that each flow one gallon per minute, then you've got no oil pressure because oil's going out of the oil channels as fast as it comes in. So excess clearances between the bearings as a result of excess bearing wear will bleed off oil pressure, particularly at low rpm when the pump's spinning slowest. While several things can cause a loss of oil pressure at low rpm, this is one sign of severely worn bearings in the lower end.

Noise in the Engine

    Most neophyte car guys have heard of rod knock, if not heard it themselves. Rod knock -- a steady hammering that increases linearly with rpm -- happens when excess clearances causes by bearing wear cause the rod big-ends to hammer against the crankshaft at the top and bottom of the piston stroke. Rod knock is a sure indicator of worn bearings. But there's another kind of engine noise that can indicate worn lower-end bearings, and that can happen in the valvetrain and lifters. Many engines have a "priority main" oiling system, meaning that oil pressure goes to the crankshaft and rods before it does anywhere else. Excess oil leakage at the crank and rods can starve the valvetrain of needed pressure, resulting in a seemingly innocuous lifter tap that actually indicates worn crank or rod bearings.

Worn Belts and Transmission Noise

    Here's an interesting symptom that tends to slip the average mechanic's mind. Your main bearings have two kinds of bearing face; the regular bearing face that the the crankshaft rides on, and a "thrust bearing" surface in the engine block that keeps the transmission from moving back and forth. The thrust-bearing surface, which is vertical in the engine block, can wear just like the main bearing face. If there's enough room on the rod journals, worn thrust bearings can allow the crank to move forward or backward enough to cause excessive edge-wear on the belts, or backward enough to jam the torque converter into the transmission. The latter may cause transmission noise at the least, and at worst can break the transmission. The metal dust resulting from the force of the torque converter pressing back on the oil pump can clog the filter, potentially causing fluid pressure loss -- and clutch slippage -- in the transmission as a result of the clogged filter and damage to the pump.

Senin, 24 Mei 2010

Troubleshooting Auto Brakes

Troubleshooting Auto Brakes

The brakes are the most important safety system on every automobile. It is the responsibility of every motorist to ensure their brakes are in proper working order, not only for their own safety, but also for the safety of their passengers and other users of the road. Basic troubleshooting of automobile brakes is not difficult, and every motorist can easily learn how to look for simple symptoms of brake issues that, if left unattended, could develop into serious problems down the road.

Instructions

    1

    Pay attention to unusual noises while driving and when braking. A high-pitched squeal that can be heard, even when the brakes are not being used, may be caused by the wear indicators that are often built into disc brake pads to purposely make this sound as a warning that the pad linings are nearly worn out. If the pads are old, check the lining thickness. If a quiet brake squeal is heard with brand new pads, wait until the vehicle has been driven for about 300 miles of city driving to allow the new pads and the discs to wear together. If the pads are neither new nor old, consider installing noise-reducing shims on the backs of the brake pads. A very loud crunching, scraping or grinding noise might indicate a complete failure of one or more brake pads, and the brakes should be serviced immediately.

    2

    Check for pulsation or vibration during braking. In the mechanic's world, this is often referred to as brake judder. Judder can be caused by cracked or unevenly worn discs, in which case the defective disc must be resurfaced or replaced. Improper tightening of the wheel lug nuts can put uneven forces on the disc, sometimes causing the disc to warp, causing brake judder. Judder can also be the result of discs that are not installed straight, or brake drums that are out-of-round.

    3

    Check for vehicle pull during braking. If the vehicle pulls to one side when the brakes are applied, it usually indicates that the front caliper on the side away from the direction of the pull is seized and not closing properly. The caliper should be disassembled, inspected and lubricated. Brake pull can also be caused by restricted or plugged brake lines, or by a failure of one chamber of the brake master cylinder. The brake pads on the side opposite to the pull may have oil or grease on the lining surface. If the pull is accompanied by a loud grinding noise, it may indicate the brake pads on the side of the pull have failed completely, and the metal pad backing plate is grabbing the disc. Other possible causes not related to the brakes include poor front-end alignment and improperly inflated or mismatched tires.

    4

    Check if the brakes grab suddenly when applied. This can indicate problems with the vacuum booster or the proportioning valve. Grabbing brakes might also be caused by contamination on the brake pads or shoes. Dust and road grit can get into the pad linings, causing increased friction between the pads and the rotors. This often happens after extended driving on dusty, dirt roads.

    5

    Check the "feel" of the brake pedal. Experienced drivers know the normal feeling they get when they press the brake pedal. If the pedal feels harder or higher than normal, it can indicate problems with the brake power booster. A soft and mushy feeling can be caused by trapped air in the brake lines, a low brake fluid level or a problem with the master cylinder. If the brake pedal sinks to the floor, it is likely the brake fluid level is critically low, or there is a major failure of the master cylinder.

    6

    Test the power brake operation. With the engine running, push, and hold, the brake pedal. The pedal should have a firm feel, and it should not drop towards the floor with time. A soft or spongy feel indicates air is trapped in the brake lines, and the brakes should be bled, to remove any air bubbles. A firm, hard feel can mean that the power booster is defective and must be serviced or replaced. If the pedal feels normal, but slowly drops toward the floor with time, it is likely there is a problem with the master cylinder, and the cylinder should be replaced. As an additional check, hold the brake pedal down with light, steady force, with the engine off. The pedal should feel high and hard. Now, start the engine, while still holding the pedal down. The pedal should drop, slightly, and have a normal feel. If so, the power booster is probably working properly.

    7

    Check the level in the brake fluid reservoir. This is usually a semi-transparent plastic container, located near the rear of the engine compartment on the driver's side. There are clearly visible marks on the side of the reservoir for "Full" and "Minimum" levels. The fluid level should be between these marks. A too-low fluid level can result in a soft or mushy feeling, when the brake pedal is pushed. Bring the level up to the "Full" mark, using new brake fluid that meets the manufacturer's specification. On older vehicles, the brake fluid reservoir might be made of metal, and the cap must be removed, to check the fluid level.

    8

    Check the brake fluid for contamination, by opening the reservoir, and taking a good look at the fluid inside. It should have a homogeneous color and a semi-clear appearance. If the fluid is brownish in color, if scum or foam is floating on the surface or if any contamination is visible, the entire brake system should be drained, flushed and refilled with new fluid that meets the manufacturer's specification.

    9

    Check the system for fluid leaks, especially if the brake fluid level was found to be low. Check the ground, underneath the vehicle, after it has been parked in one place for awhile, and look for wet spots where fluid has dripped. Note the location, and begin your search, directly above that place. The most probable places for leaks are the connection points between the brake lines and the master cylinder, as well as the flexible brake hoses that join the brake lines to the brake cylinders at each wheel. The brake cylinder seals are also a common leak location.

Minggu, 23 Mei 2010

The High Beams Won't Stay in Place on My 2000 Chevy Monte Carlo

The high beam headlights are an important component your 2000 Chevrolet Monte Carlo's safety system. Headlights that move around and poorly track on the road are just as dangerous as burned out headlights. If the headlights won't stay in place on your Chevy Monte Carlo, the problem is in the assembly. There is something loose, either the socket, the bulb or the screw. The solution is to take the headlamp assembly apart and make sure everything is in working order.

Instructions

    1

    Open the hood of your Monte Carlo. Remove the screw from on top of the headlamp assembly with a Phillips head screwdriver.

    2

    Remove the headlamp's plastic retainer by pulling it straight up. Pull the assembly away from the vehicle and remove the electrical connector. Remove the smaller round dust cap to gain access to the high beam bulb.

    3

    Use a clean cloth to rotate the bulb counterclockwise and remove it from the assembly. Remove the electrical connector from the bulb by raising the lock tab and pulling the connector away from the bulb's base.

    4

    Reconnect the electrical connector, making sure the lock tab snaps over the base of the bulb. Lightly pull on it to make sure it is secure. Insert the bulb into the assembly and rotate it clockwise until it clicks into place.

    5

    Connect the electrical connector to the rear of the assembly until it snaps into place. Reattach the round dust cap to the high beam bulb. Place the assembly into the vehicle and reattach the plastic retainer until it clicks into place. Wiggle the assembly, testing it to ensure it is secured into place. Reattach the screw and close the hood.

87 Nissan Van Troubleshooting

87 Nissan Van Troubleshooting

The 1987 Nissan Van is a rare four wheel drive style minivan, that seats seven passengers and has second row captain's chairs with a swivel action for facing forward and backwards. It does not use a computer system, and an electronic reader is not necessary for troubleshooting. Although its four speed engine requires basic mechanical knowledge and observations for troubleshooting, it is crammed into a small box with very little room available for making repairs.

Instructions

    1

    Monitor the temperature gauge as you are driving. If the temperature rises rapidly, shut off the van and open the hood. The engine is very tight in the engine compartment and it has difficulty cooling. Replace the engine hoses if you see steaming and smoking when the vehicle overheats.

    2

    Test the power if the engine is completely dead. Test the interior dome light and dash lights for power before using a voltage meter to test the battery and the alternator. Use jumper cable to charge the battery and start the vehicle. If the battery drains on a regular basis, it must be replaced.

    3

    Open the window and the hood to listen for a clicking sound when the engine does not crank. The sound means the starter teeth are locked and the engine will not start. Locate the cylinder shaped starter beneath the motor. Use a hammer to tap the starter and unlock the teeth. Start the vehicle.

    4

    If the engine will crank but will not start, the spark plugs must be replaced. In addition to the plugs, the fuel injectors may need cleaning and the fuel pump may be broken. Always begin with the plugs because they are the least expensive to replace.

    5

    Drive the vehicle and make several turns. If the van is difficult to turn, the power steering pump may require servicing. The four wheel drive lockers may also be stuck on the hubs. Shift in and out of four wheel drive several times to release the lockers.

Sabtu, 22 Mei 2010

Troubleshooting a 2002 Jaguar X-Type Front Wheel Bearing

Depending on who you ask, the 2001 to 2009 might have been the last "real" Jaguar ever produced. At least, the last Jaguar that didn't look like an Aston Martin. Based largely on the popular Ford Mondeo sedan, the Jag's underpinnings might not have been exotic -- but they were certainly more reliable than many Jags of the past. This includes the suspension and drive, which in turn includes the wheel bearings. But, wheel bearings are wear items after all, and they will go bad sooner or later.

Instructions

    1

    Find a smooth, straight road -- preferably freshly paved asphalt. The X-type has always been known as a fairly smooth and silent automobile, but small imperfections in the road, like cracks and potholes, can make noise isolation difficult. All the better if you can find a tunnel with fresh pavement and conduct your test there at night. A tunnel is a perfect sound-reflection chamber.

    2

    Accelerate to about 15 mph, then continue to accelerate gently to 50 mph. Under light acceleration, a bad wheel bearing will typically manifest as a moaning sound and a light vibration felt through the front floor pan and steering wheel. Bad wheel bearings will also generally exhibit "tip-in moan," meaning that noises and vibrations occur primarily at a certain throttle setting or at a certain speed.

    3

    Feel and watch for a shake in the steering wheel, front floor pan, seats and front sheet metal during acceleration or deceleration. Shake is usually accompanied by a low-frequency vibration, which may or may not get worse when you lightly apply the brakes.

    4

    Accelerate to between 60 and 70 mph, if you deem it safe with a potentially damaged wheel bearing. At high speed, you may hear a higher frequency rumble or buzz, accompanied by a rapid vibration in the seat, floorpan or steering wheel. At high speed, shift the transmission into neutral and coast; if the sound and vibration remains unchanged, then you've at least eliminated the engine as a possible problem.

    5

    Listen and feel for the aforementioned symptoms while cornering; popping, clicking, grinding and vibration while turning may be due to either a worn, damaged or incorrectly installed wheel bearing, or to a similarly malfunctioning half-shaft if you own an all-wheel-drive X-Type.

    6

    Jack the front end of the car up far enough so that the suspect front wheel dangles off the ground. Grasp the top and bottom of the tire and try to tilt the top of the wheel in and out. If the wheel tilts at all, then it's time for a new bearing. Unfortunately, this isn't a job you can do at home, unless you've got a bearing press and the appropriate press fittings.

How to Troubleshoot a 1986 Honda Civic Hatchback Si

Third-generation Honda Civics were manufactured from 1983 to 1987. The 1986 Civic Si hatchback was the performance-oriented model, offering light weight, nimble handling and fuel economy. Though the Honda Civic has become known for its long-term reliability, general malfunctions become increasingly likely on older models, especially those with high mileage. Regular troubleshooting should be performed on your 1986 Honda Civic Si hatchback to ensure its continued performance and reliability.

Instructions

    1

    Inspect the entire vehicle for signs of rust or corrosion, paying special attention to the exhaust system and engine compartment. Given the age of your 1986 Civic, rust is likely to develop in places exposed to the elements. Rusted exhaust piping can cause a noisy exhaust note, as well as various performance and emissions malfunctions. Rusted chassis components can negatively affect your Civic's handling and general driving characteristics. Rusted components should be replaced or repaired immediately to ensure the rust does not spread to other parts of the vehicle, where it's likely to cause more complicated issues.

    2

    Unplug the spark plug wires from the tops of the spark plugs, accessible on the top of the engine valve cover. Remove each of the spark plugs with a socket wrench. Inspect the bottoms of the plugs for signs of soot buildup or corrosion. This is generally a sign of an overly rich fuel mixture, or engine oil leaking into the cylinders. Overly rich fuel mixtures are often caused by malfunctioning engine sensors, such as the fuel pressure or oxygen sensors. Generally, exhaust backfiring will also occur. The most likely cause for leaking engine oil is blown engine gaskets, such as the cylinder head gasket.

    3

    Listen for signs of malfunctioning suspension components while driving, such as creaking or banging noises. This is often caused by blown shocks on high-mileage Hondas, which also leads to a bouncy ride and poor handling. Other common suspension malfunctions include broken or disconnected components, such as control arms or tie rods. Visually inspect the suspension system from the underside of your Civic, ensuring that all components are securely connected and free of damage.

    4

    Listen for rattling noises while driving. Rattles originating from the exhaust system are most likely caused by loose heat shields and/or disconnected exhaust hangers. Ensure that all exhaust system components are securely connected, and that the exhaust piping is properly connected to the hangers on the underside of the Civic. Rattles originating from the Civic's interior are common due to loose interior panels. Interior panels are secured with plastic clips and various Phillips-head screws. Gently shake the dash and interior components to reproduce rattles, and secure any loose interior panels.

My 1999 Yukon 4WD Makes Clicking Noise

General Motors produces the Yukon, a full-sized sport utility vehicle. The Yukon has been in production since 1992 and is available with a variety of options, such as four-wheel drive, the XL package and the Denali package. The Yukon is similar to the Chevrolet Tahoe and Suburban in both drive train and engines. The 1999 Yukon has had factory recalls, such as seatbelt and fuel system problems.

Instructions

    1

    Check to see if the 1999 Yukon's engine lifters are "sticking," which will cause a clicking noise. Start the Yukon and open the hood. If the clicking noise is coming from around the center of the engine, then most likely the lifters are sticking. When the engine oil is worn and it thickens, it will produce deposits or "engine sludge." The deposits cause the engine lifters to stick when trying to move up and down, which causes the clicking noise.

    2

    Check to see if the Yukon has an exhaust leak or if the exhaust pipes are loose. Start the Yukon and inspect the exhaust pipes for any holes, pinched pipes or rusting areas. Listen to the muffler to see if the noise is produced there. Check to see if any clamps are missing.

    3

    Check the oil pressure in the 1999 Yukon. The Yukon is equipped with an oil pressure gage located in the instrument panel. If working properly, the low oil pressure light will be displayed in bright orange. Manually check the engine oil if the oil pressure gauge is not working. Park the Yukon on a level area and leave the engine off for at least five minutes. Pull out the engine oil dipstick and check the oil level.

1991 Buick Regal Won't Start

If your 1991 Buick Regal will not start, the process of getting it started again could be a long one. However, one of the first places to look is the ignition system because a faulty component within it could easily prevent your Regal from starting. By beginning with the battery, moving to the ignition then onto the starter and starter solenoid, you can quickly eliminate the most logical reasons the car will not start.

Instructions

    1

    Disconnect the negative battery connections with a wrench and clean the contacts with a wire brush to remove corrosion and battery acid. Reconnect the battery and attempt to start the Regal. If it does start, the issue was due to poor contact with the battery.

    2

    Jump-start the Regal by connecting the battery to a working car battery via a pair of jumper cables. If the Regal starts, replace the battery with a new one.

    3

    Shift the Regal into neutral, set the parking brake and crawl under the car. Locate the starter between the transmission and the transmission housing. The starter solenoid bolts onto the starter housing. Locate the two large metal posts on the back of the solenoid and bridge them with the blade of a screwdriver. This will short out the solenoid and force a direct connection between the starter and the battery. If the motor in the starter turns on and runs smoothly, move to the next step. If not, replace the starter.

    4

    Place the positive lead wire of a multimeter against the right contact on the starter solenoid. Place the negative lead against the casing of the starter. Have an assistant attempt to start the vehicle. If the meter does not read at least 12 volts, replace the solenoid.

99 Ford Ranger SRS Trouble Codes

99 Ford Ranger SRS Trouble Codes

The Ranger's Supplemental Restraint System is an interesting kind of anachronism, particularly in this age of sophisticated and networked self-diagnostics. The airbag system, for reasons of safety and redundancy, doesn't rely on the truck's primary computer -- instead, it utilizes an older an simpler technology to activate the airbags and to diagnose when something's gone wrong.

The SRS Computer

    Ford's SRS system doesn't work through the engine control computer the way you'd think it would. While government mandates forced Ford and other companies to produce second-generation computers and control systems for the engine, the comparatively simple SRS system got away with using a stand-alone computer largely based on the first-generation OBD-I computer. In an interesting nod to its origins, the SRS's computer communicates its code failures using the old-school blinky-light method.

Pulling Codes

    If you've ever pulled the codes on an old ALDL -- assembly line diagnostic link -- car, then you know something about the procedure here. When you turn the ignition key to the on position, the computer will automatically communicate the codes to you using the airbag light on the dashboard. If something's gone wrong with the airbag system, the airbag light will flash a number of times, pause, then flash again. If, for instance, it flashes four times, pauses, then flashes two more times, you've got a code 42.

Clearing Codes

    You've likely experienced a bit of trouble finding specific information online as to how to clear airbag codes -- troubles you'll continue to find here for a good reason. The airbag system is one of the few things on your truck that shouldn't be messed with by anyone but a professional. Airbags can kill you in at least two different ways: either by not going off when they should or by going off when they shouldn't. So, you'll just have to take it to a shop to get it fixed, if you've got codes. But at least, you'll know what needs to be fixed when you do take the truck in for repair.

Solid On, Codes 12 Through 24

    A solid-on light means either that the airbag system isn't workin, or that there's an active code keeping it from working properly. If you see a solid-on light, turn the key off and back on to initiate the blinky-light diagnostic. Code 12 indicates lost power supply to the computer, 13 means that the airbag circuit has shorted to a ground. Code 14 means that the crash sensor itself has shorted to a ground, and 21 tells you that the diagnostic monitor isn't properly mounted to the vehicle. Code 22 means that the "safing" sensor output circuit has shorted to the battery voltage. Code 23 tells you that the memory clear circuit is improperly grounded, and 24 means that the system disarm feature has failed or that there's a diagnostic monitor fault.

Codes 32 Through 53

    Codes 32 and 33 mean there's either high resistance or an open circuit, such as a cut wire),in the driver- or passenger-side airbags, respectively. Codes 34 and 35 are exactly the opposite: a driver- or passenger-side wire with low resistance or has shorted out. Codes 41 and 44 refer to the right-side crash sensor, meaning that it's not connected to the computer or that it isn't mounted properly to the truck , respectively. Codes 42 and 45 mean the same things for the left-side sensor. Code 53 means that there's high-resistance, such as a cut or damaged wire or sensor internals, at the front sensor, or that there's a diagnostic monitor failure. Code 51 means that the thermal fuse in the airbag monitor has blown, and 52 tells you that there's a problem with the system's back-up power supply or battery.

Jumat, 21 Mei 2010

My 1998 Mercury Sable Won't Start

There are a couple of things that can cause a Mercury Sable not to start, but given the age of a 1998 model, there can be both electrical and mechanical issues that are causing this. If proper maintenance intervals have been followed, the most likely culprit is just a dead battery. There are a number of steps that can be taken to fix a dead or dying battery, and to see if there are more serious issues preventing the car from starting.

Instructions

    1

    Start the Mercury Stable as you usually do. Listen for the engine to chug, which indicates it is turning over. If there is no chugging, then look at the dashboard lights. If the lights do not come on, or if they are only flickering, then the battery is dead or dying.

    2

    Turn the car off and pop open the hood. Inspect the car battery for foam. If it is foaming, the battery is leaking acid and a tow truck is needed. A professional mechanic has to deal with the battery due to the possibility of acid burns. If there is no foam, then strike the battery post clamps with a shoe, as the clamps may need to reconnect. Try starting the Mercury again. If it still does not start, the battery needs to be replaced, or it needs a jump.

    3

    Jump-start the Sable by first making sure the Mercury is turned off. Park a functioning car hood-to-hood with the Mercury. Open both hoods. Connect one end of the red jumper cable to the positive terminal on the Sable and the other end to the positive terminal on the other car. Connect one end of the black cable to the negative terminal on the other car and the other end to a bare metal part of the Sable. Start the functioning car, let it idle for five minutes, and then start the Mercury. Let the Mercury run in place for half an hour to fully recharge the battery. If, however, this does not work, your battery may be beyond revival and need to be replaced.

    4

    Replace the battery in the Sable by first turning off the car. Take off the battery post clamps, by unscrewing the O-ring clamps with a flat-head screwdriver, and remove the retaining clamps with the flat-head screwdriver. Pull the battery out by the handle, and slide in the new battery. Screw down the retaining clamps and electrical clamps, being careful to not over-tighten the screws. Try to turn the Sable on. If the car lights come on but the engine does not start, the engine may be flooded.

    5

    Enable the "Clear Flood" mode that will clear a flooded engine. A flooded engine is when there is fuel on the spark plugs that is stopping them from sparking. To enable the Clear Flood mode, you need to depress the accelerator all the way to the floor, before repeatedly turning the ignition to the "On" position. This triggers the Clear Flood mode, which makes the engine pump air instead of fuel, thus drying the spark plugs. Do this for five minutes, then take your foot off the pedal and turn the car off, taking the keys out of the ignition. After a minute, the car should start. If it still doesn't, there may be mechanical problems necessitating a professional mechanic with diagnostic equipment to fix them.

Rabu, 19 Mei 2010

How to Troubleshoot a Ford Thermostat

How to Troubleshoot a Ford Thermostat

The thermostat in a Ford uses a valve filled with mercury to measure the temperature of the coolant in the engine. As the temperature rises, the valve opens and allows more fluid to flow through the engine. This keeps the Ford from overheating. Whether the thermostat in your Ford stays closed and causes overheating, or it stays open and prevents the Ford from properly heating the engine, you can troubleshoot the thermostat to determine if replacement is necessary.

Instructions

    1

    Drain the coolant from the petcock located on the bottom of the radiator. Use a pair of pliers to open the petcock if necessary. Remove the thermostat from the engine. To do so, follow the upper radiator hose to the location where the hose connects to the engine. Pry the hose clamp off the hose with a pair of pliers and remove the hose from the T-Stat housing. Remove bolts that secure the T-Stat housing to the engine with a socket set, remove the housing and pull the thermostat out of the engine.

    2

    Fill a pot with water so the thermostat rests fully submerged in the water. Place the thermostat in the pot with the spring resting against the bottom of the pot.

    3

    Place a cooking thermometer in the pot with the thermostat.

    4

    Heat the water until it reaches 190-degrees Fahrenheit. The thermostat will remain closed until it reaches 190-degrees Fahrenheit. Once the temperature surpasses this, the thermostat should open up and the spring should compress. If it does not open, the thermostat is defective and needs a replacement.

    5

    Reattach your thermostat or install its replacement. Place a new gasket between the engine and the thermostat housing and secure everything into place with the bolts. Secure the radiator hose back to the T-Stat housing and drain the fluid back into the radiator.

What Are the Causes of a Fuel Smell From the A/C on a 2006 Toyota Corolla?

There are many reasons why your A/C can smell like gas, but they all boil down to a broken part in the fuel delivery system. Normally, Toyota installs reliable fuel systems in all their models; however, normal road wear can cause it to malfunction.

Tank

    The fuel tank may cause a fuel smell to be emitted from the air-conditioning even though it is located to the rear of the car. The fumes of the tank may permeate the rest of the car and get trapped in the A/C vents. When the air conditioner is turned on, it expels the trapped fumes and makes your car smell like gas. This can be an expensive repair, given the danger of repairing a tank that is coated in gasoline. It can only be detected by an equipped mechanic, as the hole may be too small for the naked eye.

Lines

    Another possibility is a rupture along the fuel lines leading from the tank to the engine. This can be detected by parking your car in a new spot and checking for spots the next morning. If there are spots, then the line will have to be replaced by a mechanic. You can wrap the line in duct tape, but the gas will eventually eat through.

Pump

    The fuel pump may have broken the seals The pump is an aluminum cylinder the size of a soda can that's located under the body, just along the fuel line. It will be covered in gas if there's a leak.

Carburetor

    The carburetor may be causing the fuel smell if it's not containing the fuel-air mixture. There is no way to detect this at home; you have to visit a dealership mechanic to detect it. The equipment to test for carburetor leaks is not widely available. A diagnosis is confirmed only after dismantling of the carburetor.

Selasa, 18 Mei 2010

Possible Causes of an Air Conditioning Compressor to Not Come On

Possible Causes of an Air Conditioning Compressor to Not Come On

Air-conditioning malfunctions can be difficult to diagnose. Even the most basic system may employ electric relays and timers to govern compressor operations. More complex controls can interrupt function to protect system components or regulate the temperature of the car passenger compartment. Still other crucial parts may simply wear out over time. Discovering which part is at fault can be confused by the interactions they all share. Although most air conditioners are somewhat simple in basic operation, multiple requirements must be met for reliable function to take place.

Highs and Lows

    Special tools are required to accurately measure refrigerant levels.
    Special tools are required to accurately measure refrigerant levels.

    The leading cause of compressor engagement problems may be a lack of refrigerant in the system. The compressor is cooled and lubricated by the refrigerant and the oil it carries. The amount of refrigerant in the system can be reduced through small, almost imperceptible leaks. When the amount of refrigerant dwindles below a certain level, system pressures drop to a point that endangers the compressor. Power to the compressor clutch is interrupted by a safety switch that keeps the pump from starving. Conversely, system pressure can climb beyond safe levels due to clogs in the system plumbing, or unintended overfills. Then too, power to the compressor clutch is cut off, and the pump is kept from engaging as long as pressures are abnormal.

On and Off

    The devices that protect the compressor from starvation and excessive pressure can fail or be ruined in execution of their duties. Some compressors are protected from excess pressure by a relief valve or plug. When pressure exceeds safe levels, the core of the plug is expelled along with the system contents. More recent designs accomplish this safeguard without venting refrigerant to the atmosphere, but either design disallows any further compressor function once triggered. High and low pressure safety switches might be bypassed as an aid to diagnosis. The suspect switch is replaced if normal operation resumes while the bypass is in effect.

In a Clutch

    The presence of proper voltage at the clutch coil is no actual assurance of coil or clutch function. The clutch coil is energized to produce a magnetic field that attracts the clutch disc. When the disc engages, the engine belt that spins the coil pulley then drives the compressor. The coil can grow weak over time or become ineffectual at certain temperatures and fail to attract or hold the clutch disc. The gap between the disc and coil has to be correct as well. The gap can become too wide from loss of friction material on the disc or improper spacing during compressor repair or rebuilding processes.

In Control

    More sophisticated air-conditioner systems, like those with thermostatic controls or dual comfort zones, employ more sensors and switches than basic units. Large passenger vehicles often have an entirely separate climate control system for the rear compartment that shares the compressor with the dash unit. Electronic modules and thermostatic switches that allow intricate adjustments and functions can disrupt power to the compressor on purpose or in error. Hunting down the exact part responsible for a malfunction can be challenging, even for seasoned technicians. Specific system knowledge and complex test equipment is sometimes needed for accurate diagnosis, but before you hock the family silver and head to the dealership, you might save the day simply by checking the fuses of your vehicle.

How to Troubleshoot the OBD2 Code PO700

How to Troubleshoot the OBD2 Code PO700

The P0700 OBD2 code is a general transmission error code triggered when there is a transmission related problem in a vehicle. The P0700 code is accompanied by secondary codes by the vehicle ECM to help pinpoint the actual malfunction. Diagnosing a P0700 problem entails having your vehicle scanned to isolate the issue. Without knowing the secondary codes, a P0700 error code can be anything from a sensor failure to low line pressure in a transmission so having your vehicle scanned to pinpoint the underlying issue is vital to avoid expensive uninformed repairs.

Instructions

    1

    Record any symptoms your car is exhibiting. You need to make a log of the problems and when they occur. Providing the log to a mechanic to help diagnose the problem.

    2

    Use a scanning tool to scan your vehicle. A variety of private companies sell OBD2 scan tools that you can use to scan your own vehicle for error codes. While scan tools are available for purchase at many automotive supply stores, most scanners will only read engine control module codes. Since the P0700 is a transmission control module error, you will need to confirm that the scanner can display TCM errors.

    3

    Take your vehicle to a professional to be scanned. A scan will be able to read the secondary error codes your vehicle is stores in addition to the P0700 code. Many large automotive chain stores will provide OBD2 scans for free, or you can have your vehicle scanned by your dealership or a independent shop.

How to Retrieve Fault Codes for a 2003 BMW 525

How to Retrieve Fault Codes for a 2003 BMW 525

Since 1996, all cars sold in the United States must come with an onboard diagnostics (OBD II) compliant diagnosis device installed. BMW puts a service indicator computer with a self diagnostic function on all cars, including the 2003 BMW 525. The system alerts the driver that there is a problem with the car through an engine warning light. The service indicator computer also provides fault codes to indicate the specific problem(s). These codes can be read with an OBD II reader connected to the BMW's data link connector (DLC).

Instructions

    1

    Locate the data link connector in the 2003 BMW 525. It is located directly above the trunk release button, behind a small panel that opens.

    2

    Insert the ignition key and turn it to the "On" position, but don't start the engine.

    3

    Plug an OBD II reader connector into the DLC and initiate the device.

    4

    Follow the reader's instructions to retrieve the fault code(s) from the service indicator computer.

    5

    Compare the fault code(s) to the ones listed on the OBD Codes: BMW OBD-II Trouble Codes page (see "Resources"). This will show the specific problem(s) with the BMW.

Could a Bad Theft Deterrent Switch Make a Car Not Start?

Could a Bad Theft Deterrent Switch Make a Car Not Start?

Theft deterrent systems are built to do just what their names indicate. However, they have been known to prevent the owner from starting the vehicle as well. Having your ignition switch go dead as you drive could be dangerous. This is one reason why information on these systems can be beneficial to vehicle owners.

Function

    On a theft deterrent system, the switch is equipped with a transponder receiver inside it. This receiver communicates with an ignition key through a chip located within the key. These signals go to a vehicle's computer system and indicate whether or not to allow the vehicle to start. A theft deterrent switch can make a car not start if its receiver malfunctions or is faulty.

Diagnose

    There are several reason why a theft deterrent switch can make a car not start. One reason is that the system loses the ability to read the key when it's inserted into the ignition due to a faulty chip within the key. There is also a chance that faulty wiring could be to blame.

Time Frame

    Dealerships have special tools that can determine the problem that prevented your vehicle from starting. After fixing the problem, they will also have to reprogram the system, which costs around $100 as of 2011. The reprogramming process can take about half an hour to finish.

Senin, 17 Mei 2010

Electrical Problems in the Hyundai Accent

The Hyundai Accent was introduced in 1994; it is a sub-compact car available in sedan and hatchback. Edmunds.com reports that -- despite its low price -- the Accent is well-built vehicle with solid performance. The 2011 Accent is available with automatic or manual transmissions.

Exterior Lights

    The National Highway Traffic Safety Administration indicates that multiple recalls relating to the Accent's exterior lights were issued in 1995, and from 2005 to 2007. The recalls included a faulty headlamp dimmer-switch and brake light failure. The recall notice indicates that exterior lighting malfunctions might lead to a crash.

Windshield Wiper Motor

    The NHTSA reports that windshield wiper recalls were issued from 1996 to 1997, and in 2000. Recall notices stated that -- due to a manufacturer's defect -- the Accent's windshield wiper motor might malfunction. A faulty wiper motor might result in reduced visibility, leading to a potential accident.

Airbags

    The NHTSA has investigated multiple Accent airbag complaints. Complaints include injury due to deployment -- and lack of deployment -- upon accident. The primary indicator of potential airbag failure is the illumination of the SRS light on the dash panel.

How to Check Auto Coils

How to Check Auto Coils

Electricity can be described in terms of amperage (the amount of electrical flow) and voltage (the energy level or "temperature" of the electricity). An ignition system takes the 12 volts coming from your car's electrical system and amplifies it to the 20,000 volts or more, which is required to ignite the fuel charge. The 12-volt charge goes through a number of large wires before transferring to thousands of smaller wires, wrapped around the output terminal. The smaller wires can't handle as much amperage, so they compensate by increasing the voltage of the coil. Testing the coil output is a pretty simple procedure, requiring only a few basic tools and an understanding of how the coil works.

Instructions

    1

    Unplug the coil wire from the top of the distributor and push an old spark plug into the end of the coil wire. The spark plug may actually plug into the coil wire, but odds are it won't fit snugly. Wrap some electrical tape all around the plug (but not on the threads) and wrap it around the top of the coil wire until the two are firmly connected.

    2

    Lay the plug and wire on top of a rolled-up rag so it doesn't come into contact with anything metal. Turn your car's ignition to "On," but don't try to start the car. Grasp the tape-wrapped portion of the plug with a pair of insulated pliers or channel locks (the electrical tape may be enough to insulate you from the coil's charge, but don't count on it; a high-voltage shock may or may not kill you, but it's guaranteed to really hurt).

    3

    Tap the exposed metal of the spark plug on a metal part of your engine. The intake manifold may or may not provide a sufficient ground, but the alternator bracket, cylinder head or engine block almost certainly will. Upon tapping the plug, you should see a bright blue-white spark jump across the spark plug's electrodes. If the spark is thin and yellow and your don't hear the pronounced "snap" of the jumping electricity, then the coil isn't providing sufficient output. Don't leave the plug in contact with a ground for more than 1/2-second; repeatedly tapping it will give you a quantifiable result without burning up the coil.

    4

    Turn off the ignition. Remove the plug from the coil wire and reconnect everything, but remove the coil-end of the output wire. Break out your digital multimeter and set it to read ohms of resistance (abbreviated as "", the Greek symbol for Omega). Place your multimeter's probe terminals on the power-in and ground terminals on your coil; you should get a reading of between 0.5 and 1.3 ohms, depending on the coil. Larger coils will read higher than smaller ones.

    5

    Leave the positive probe attached to the positive terminal and touch the negative probe to the output where the coil wire attached; you should get a reading of between 5,000 and 11,000 ohms, depending on the size of the coil. Any more than 1.5 ohms on the first measurement or 14,000 on the second almost always indicates excessive internal resistance, which means your coil is shot.

How to Do Automotive Diagnostics

How to Do Automotive Diagnostics

Performing diagnostic tests on a vehicle depends on the year of manufacture. Vehicles after 1996 operate under the second generation of On-Board Diagnostic coding. Also, if your car or light truck is manufactured after 2008, it will likely have a tire pressure monitoring system. There are other self-monitoring systems in the brakes and in airbags. All of these systems can be accessed with a scanner through the diagnostic outlet usually on the driver's side of the vehicle. If your vehicle predates 1996, diagnostic procedures vary by make and model. You will have to consult your manual and resources specific to your vehicle.

Instructions

    1

    Visit an automotive retailer and shop for a code scanner. The more you pay, the more features the scanner will have. Some higher end diagnostic tools are multilingual or can diagnose more than one system. Cheaper tools are dedicated only to OBD-II codes. Also, the scanner you chose to buy will also depend on which trouble indicator light is active on your vehicle. You will have a regular "Check Engine" light, as well as a separate light for brakes, airbags, and tires. If your airbag light is active, you should drive your car to a mechanic; diagnostic tools are not as widely available, and the needed repairs are more complex.

    2

    Hook the diagnostic scanner to the computer outlet on the driver's side of the car. For most cars, this outlet is under the dash, somewhere between the gas pedal on the right and the hood release on the left. It is often black in color, and will feature 16 pin receptors. The plug at the end of the scanner's cable should easily fit, so do not jam it in. If you cannot locate this outlet, there are websites like CarMD.com that will tell you where it is.

    3

    Turn the scanner on. You will have to do this for some diagnostic tools, but not for others. Some scanners will turn themselves on once a link with a vehicle's diagnostic system is sensed. The process might differ slightly by brand and diagnostic system, but the process is basically the same

    4

    Insert your key into the vehicle's ignition and turn to the "On" or "Run" position. This also may vary according to vehicle type, so consult your manual.

    5

    Wait a few seconds while the diagnostic system and the scanner establish a connection. You will know the two systems are linked once a trouble code appears on your scanner.

    6

    Reference the trouble code with the scanner's owner manual. The manual will have a list of codes and definitions. If you are using an OBD-II scanner, these codes will be generic ones approved by the Society of Automotive Engineers. Manufacturer specific codes will likely not be in either the scanner or the vehicle's manual. Write the code down if this is the case, and look it up online. There are many websites devoted to trouble codes and their definitions. OBD-codes.com is one, and it lists them by manufacturer.

Minggu, 16 Mei 2010

Signs of a Bent Frame

Signs of a Bent Frame

Vehicles that have been involved in accidents where the frame is bent are typically totaled. Occasionally, a vehicle with a bent frame may avoid detection. Over time, though, the vehicle will display a variety of signs and symptoms of the problem. While no one vehicle problem is a guaranteed indicator of a bent frame, a combination of issues may result in the conclusion that a vehicle's frame has been damaged. Vehicles should always be taken to a professional mechanic or body shop for official diagnosis of a bent frame.

Visible Frame Damage

    Crawl under the car and look for damage or creases in the metal frame. Anything that looks suspicious, creased, rusted or visibly damaged in any way should be checked by a mechanic. A crease or unusual angle in the metal of the frame is a sure sign of a bent frame.

Alignment

    A car with a bent frame will always be out of alignment and pull in one direction or the other, regardless of how many times it has been aligned or how recently.

Wheels Don't Track Properly

    Vehicles with a bent frame have a tendency to do what is sometimes referred to as crab-walking or dog-walking, a name that's generated because dogs and crabs walk slightly sideways. The rear tires of a vehicle are supposed to follow exactly behind the front tires. In a vehicle with a bent frame, the rear wheels will not track the same as the front wheels.

Uneven Wear in Shocks and Suspension

    Cars are made to be balanced. A bend in the frame will put the car off-balance, causing increased wear and tear on the side where the brunt of the weight or force is placed. If your cars suspension is wearing strangely or keeps breaking or malfunctioning, have it checked for a bent or damaged frame.

Improper Fit

    Cars are large pieces of mechanical equipment, made from hundreds of other smaller pieces. The frame is the base for everything that constitutes the car. In the event that a vehicle has a bent frame, smaller pieces of the vehicle, including the body panels, will be out of line. Door and body panels may gap, not line up properly or work improperly if the frame is bent. Smaller pieces of equipment, such as mounts and bolts, may break due to the extra strain placed upon them by the changed position of the frame.

Airbag Light Codes for Fords

Airbag Light Codes for Fords

When there is a problem with a Ford's airbag, the airbag warning light will illuminate and flash a code that identifies the problem. Because airbag problems range from a lost battery feed to a shorted circuit, it is important to understand the codes so that the airbag can be properly repaired.

Codes 12 to 14

    These codes are started by a single flash of the indicator light, followed by a two-second pause. After the pause, the light will flash the number of times that corresponds to the second digit of the code. Code 12 (single flash, pause, two flashes) means that there is a lost battery feed. Code 13 (single flash, pause, three flashes) means that the airbag circuit has shorted to ground and Code 14 (single flash, pause, four flashes) means that the primary crash sensor circuit has shorted to ground.

Codes 21 to 24

    These codes are signaled by two flashes, a two-second pause and the number of flashes that corresponds to the second digit. Code 21 (double flash, pause, one flash) means the diagnostic monitor is not mounted properly. Code 22 (double flash, pause, two flashes) means the safing center output circuit has shorted to battery voltage, Code 23 (double flash, pause, three flashes) means the memory clear circuit is improperly grounded and Code 24 (double flash, pause, four flashes) means there is a system disarm failure or internal diagnostic monitor fault.

Codes 32 to 35

    These codes are signaled by three flashes, a two-second pause and the number of flashes that corresponds to the second digit. Code 32 (triple flash, pause, two flashes) means the driver side airbag has a circuit open or with high resistance, Code 33 (triple flash, pause, two flashes) means the passenger side airbag has a circuit open or with high resistance, Code 34 (triple flash, pause, four flashes) means the driver side airbag has a shorted circuit or one with low resistance and Code 35 (triple flash, pause, five flashes) means the passenger side airbag has a shorted circuit or one with low resistance.

Codes 41 to 45

    These codes are signaled by four flashes, a two-second pause and the number of flashes that corresponds to the second digit. Code 41 (four flashes, pause, one flash) means the right radiator primary crash sensor feed/return circuit is open, Code 42 (four flashes, pause, two flashes) means the left radiator primary crash sensor feed/return circuit is open, Code 44 (four flashes, pause, four flashes) means the right radiator crash sensor is not mounted properly and Code 45 (four flashes, pause, five flashes) means the left radiator crash sensor is not mounted properly.

Codes 51 to 53

    These codes are signaled by five flashes, a two-second pause and the number of flashes that corresponds to the second digit. Code 51 (five flashes, pause, one flash) means the airbag diagnostic monitor's internal fuse is blown, Code 52 (five flashes, pause, two flashes) means the back-up power supply has had a voltage boost fault and Code 53 (five flashes, pause, three flashes) means the front crash sensor has high resistance or the diagnostic monitor has failed.

Jumat, 14 Mei 2010

How to Access the On-Board Diagnostic Codes on a 2005 Ford Explorer

The On-Board Diagnostic (OBD-II) codes are stored in a 2005 Ford Explorer's computer. When a malfunction triggers one of these codes, the "Check Engine" light will appear on the instrument panel. Taking the Explorer to a mechanic will cost you just for the diagnosis, and sometimes the light is triggered by something relatively minor, like an unsecured gas cap. You can access the codes yourself with an OBD-II scanner. It's a relatively easy task, and knowing how to use a scanner will save on garage fees.

Instructions

    1

    Locate the OBD-II diagnostic part on the driver's side of your Ford Explorer, under the dash. The port is between the hood release and the gas and brake pedals.

    2

    Place the scanner's 16-pin plug into the port.

    3

    Switch the scanner on and wait for it to fully power up. This should take a few seconds.

    4

    Insert the key into the ignition and turn the Explorer to the "On" position. Don't start the vehicle. The scanner and the on-board computer are now interfaced. Any current trouble code will show on the scanner.

How to Troubleshoot a 1993 Dodge D150 Engine

How to Troubleshoot a 1993 Dodge D150 Engine

Normal wear and tear can lead to engine problems, especially in older vehicles like a 1993 Dodge D150. Troubleshooting these problems can often become a time consuming process. For every symptom of a problem, there could be two or three root causes.There is a way to shorten the process. The Dodge's diagnostic computer can provide locations within the engine to target by providing a list of codes.

Instructions

    1

    Sit behind the D150's steering wheel and place your key into its ignition. Turn the key "On" and "Off" in the following sequence: ON-OFF-ON-OFF-ON. You need to complete this sequence of turns within five seconds.

    2

    Count the number of times the check engine light flashes and write the numbers down. For example, Dodge's diagnostic code 77 will be displayed with seven flashes, a brief pause, and then seven more flashes. Code 62 would be six flashes, a short pause, and two more flashes.

    3

    Look up Dodge's diagnostic flash codes online. The D150's manual will not contain these codes or their explanations or meanings. The Internet is the cheapest option. A more expensive option is to purchase a Haynes Repair Manual covering the 1993 D150. Not only will a Haynes Manual contain the flash codes, but also pages of troubleshooting tips and the exact steps involved with repairs. Once you have found the coding explanations, copy them next to the code numbers you recorded in Step 2.

    4

    Start at the top of your list and work down. Probe and explore all areas of the engine that correspond with the flash codes. Once you are confident a code doesn't reflect the problem your D150 is facing, cross it off the list.

How Can I Check a '96 Jeep Fan Clutch for Proper Operations?

Fans on 1996 Jeeps are run by a pulley on the engine. This fan has a thermo-activated clutch, which means the hotter the engine becomes, the faster the clutch allows the fan to turn. When this clutch begins to fail, you may notice symptoms such as overheating at a stop, random overheating or the engine running hotter than usual. The fan clutch can be easily tested for proper functioning. This testing process requires only a few tools.

Instructions

    1

    Open the Jeep's hood and locate the upper radiator hose --- the rubber hose inserted into the top of the radiator. Wrap a shop rag around the hose, about 4 inches from where it plugs into the radiator, and clamp the locking pliers over the shop rag to seal the upper radiator hose.

    2

    Raise the front of the Jeep with a floor jack and place jack stands under the frame rails. Lower the Jeep until its weight is only on the jack stands.

    3

    Locate the lower radiator hose, the rubber hose that plugs into the bottom of the radiator. Block it off in the same fashion the upper hose was blocked in Step 1.

    4

    Start the Jeep and listen closely to the fan. You will hear little airflow from the fan at initial startup. Listen closely as you monitor the engine temperature. If no increase in sound is heard by the time the engine temperature reaches "Hot," then the fan must be replaced.

    5

    Turn the Jeep's engine off and attempt to spin the fan. When the engine is hot, the fan should only spin four turns at most before stopping. Anything more than four turns verifies that the fan clutch has failed.

Kamis, 13 Mei 2010

How to Troubleshoot a Bad Drive Shaft

How to Troubleshoot a Bad Drive Shaft

Troubleshooting a bad drive shaft can be frustrating. Some of the signs of a bent or imbalanced drive shaft are the same as those for an out of balance tire. Drive shafts are made of steel and aluminum. Every drive shaft has U-joints that allow it to turn at angles that create pivot points. When a drive shaft is manufactured, it is balanced by a weight welded to its side.

Instructions

    1

    Chock the wheels and make sure the vehicle is parked on a level surface and the parking brake is set.

    2

    Place a floor jack under the vehicle's lift point and raise the vehicle until there is enough room to access the drive shaft underneath. Install a jack stand underneath the car.

    3

    Put on safety glasses and move under the vehicle. Grasp the drive shaft and turn it left and right by hand to check the U-joints. If there is excessive play, the U-joints should be replaced.

    4

    Inspect the drive shaft for dents. If there are dents, it may be out of balance and need to be replaced.

    5

    Remove the jack stand, lower the jack and remove the wheel chocks.

    6

    Test-drive the vehicle. An out of balance drive shaft will cause a vibration in the floor pan and the seat. Replace the drive shaft and test-drive it again.

How to Access Onboard Diagnostics for a 1995 Cadillac

Your "check engine" light can come on for a variety of reasons, from a loose gas cap to a serious engine malfunction. To determine the difference, you can check your vehicle's error messages by accessing your on-board diagnostics. In 1995, Cadillac switched from the OBD-I diagnostic system to the OBD-II system, and which type your vehicle has depends on when during the year it was made. Neither system is difficult to access.

Instructions

OBD-I Vehicles

    1

    Turn the ignition key to the "On" position. It does not matter if you start the car or not.

    2

    Push and hold the "Off" and "Warmer" buttons on the climate-control panel until the segment check appears on the instrument panel. After the segment check is completed, the instrument panel will display any stored diagnostic codes.

    3

    Determine the cause of any codes listed (see Resources).

    4

    Exit diagnostic mode by pushing either the "Auto" or "Defog" button, or by turning the ignition off.

OBD-II Vehicles

    5

    Turn the ignition on. You can start the vehicle or leave it off.

    6

    If your instrument panel has a digital display, press and hold the "Off" and "Warmer" buttons until the entire display is lit. If your vehicle has an analog instrument panel, simultaneously press the "Off" and "Pass Warmer" buttons on the climate-control panel.

    7

    Compare any codes in the system to the manufacturer's list of code meanings (see Resources).

    8

    Exit diagnostic mode by pressing the "Econ" or "Defog" button, or by turning the ignition off.

How do I Troubleshoot an HID Headlight?

How do I Troubleshoot an HID Headlight?

Xenon High Intensity Discharge (HID) headlights allow for better reflection of road signs and markings, including intersections and objects. They produce a daylight-type white light rather than the yellow light you get from conventional headlight bulbs. According to Philips, natural daylight-type light reduces eye fatigue while driving. Problems with the bulbs can be related to the installation. You can't insert Xenon HID bulbs into non-HID lighting systems because they need special equipment. Other problems can include voltage issues and kit installation compatibility. These kinds of problems can be rectified by following some troubleshooting steps.

Instructions

    1

    Check that your headlights are HID-ready. If you insert an HID bulb into a headlight, turn it on and it doesn't work, the headlights may not be HID-ready. HID headlights need an electronic ballast and a starter. Check your vehicle documentation to make sure that your vehicle is kitted-out correctly.

    2

    Verify that daytime running lights are disconnected. If your HID headlights are an aftermarket option installed subsequent to the vehicle leaving the factory, and don't work or burn out, check you've disconnected the daytime running lights. There's not enough voltage to run both the HID lights and the daytime running lights. Look for a fuse in the vehicle's fuse box. The fuse box is usually located under the hood or in the passenger compartment near the driver. Remove the fuse marked "Daytime Running Lamp" or similar. Use the tool that's included in many fuse boxes.

    3

    Turn off automatic headlights if the kit HID lights won't start. Again, there's not enough voltage for both. You'll find a switch in the lighting control cluster. The lighting control cluster, which is the control you use to operate the lights, is in a location distinct for your vehicle.

How to Stick an Emblem Back on a Car Door

If the emblem falls off your car door, it can leave behind an awkward-looking spot on your paint. Putting the emblem back on the car is the easiest way to cover this spot back up. Fortunately, it is a fairly simple process to put the factory emblem back on your car's door.

Instructions

    1

    Clean the emblem thoroughly. Use the adhesive cleaner to remove all sticky substances and debris from the back of it.

    2

    Wash the spot on the car where you want to apply the emblem. Use the adhesive cleaner and rubbing alcohol to remove all old glue, dirt and debris from the vehicle's paint so that your emblem will bond cleanly with the car.

    3

    Apply automotive adhesive to the back of the emblem.

    4

    Apply the emblem to the door. Hold the emblem tightly in place for several minutes until the glue firmly bonds with the paint. Allow 24 to 48 hours for the glue to cure. The emblem should then be securely reattached to the door.

How to Check for Bad Main Bearings

How to Check for Bad Main Bearings

The automotive internal combustion engine has a crankshaft, rods and pistons as main components. The rods and crankshaft rotate reciprocally on protective bearing sleeves that provide a frictionless seal between the metal surfaces. Main bearing sleeves come in two half-moon sections, one that sits inside the main bearing cap and one that sits in the engine block. The crankshaft journal spins within the two. The main bearings have oil holes that lubricate the journal. Main bearings can wear with normal age, or become pitted and galled with insufficient lubrication. Checking for main bad bearings requires a process of elimination.

Instructions

    1

    Place the vehicle in park or neutral, depending upon your transmission type. Set the emergency brake and raise the hood. Do not start the engine. Pull the oil dipstick and use a rag to wipe it clean. Reinsert it and pull it up. Move the dipstick into sunlight and check for any metal reflections in the oil. Metal shavings in the oil with be the first indication of main bearing material that has sloughed off, although it could originate from the rod bearings, cam bearings or rings.

    2

    Check the "Full" oil level line on the dipstick. If low, add enough oil to bring it to full capacity. Start the engine and let it reach normal operating temperature. Look at your oil pressure gauge, or oil warning light, if so equipped. Refer to your owner's manual for the correct oil pressure in pounds per square inch for your vehicle.

    3

    Raise the engine's rpm to a fast idle. If the oil pressure reads below normal, this could indicate a problem with the main bearings, barring any defect with the oil quality and oil filter. It could also indicate a rod bearing that has spun on the journal.

    4

    Turn the engine off. Hook up the positive and negative leads of a timing light to positive and negative terminals on your battery. Clip the timing light plug lead onto your no. 1 cylinder. Refer to your owner's manual for its location.

    5

    Start the engine and point the timing down toward the crankshaft. Listen for any heavy knock or clunk coming from the engine. If you have a rod or bearing knock, the timing light will flash twice for every knocking sound. If it flashes once for every knock, you have a valve train problem.

    6

    Turn the engine off. Use a floor jack to lift the front of the vehicle and place two jack stands under the frame. Lift the rear of the vehicle and place two jack stands under the rear frame. Slide under the vehicle and don an automotive stethoscope.

    7

    Instruct an assistant to start your engine. Place the stethoscope pad against the bottom of the oil pan and listen for any clunking or knocking sounds. Have your assistant rev the engine a few time to increase the load. A knock at this location indicates a rod or main bearing failure.

    8

    Use a socket and wrench to remove the bolts holding any heat shield or skid plate underneath the oil pan. Remove the shield. If you have a structural cross-member in the way, use a socket to remove the bolts and pull the cross-member down. Remove any other part that impedes access to the oil pan cover. Use a socket to remove the oil drain plug and let the oil drain into a pan. Use a socket and extension to loosen all of the oil pan bolts. Pull the pan free.

    9

    Loosen and remove the through bolts on the engine motor mounts with a socket if you do not have sufficient clearance to pull the oil pan out. Place the floor jack under the bell housing or the crankshaft damper to lift the engine up 3 to 4 inches for clearance---no higher. Remove the oil pan.

    10

    Fit a socket and breaker bar on a main bearing cap bolt and loosen it a few turns. Switch to the other bolt on the same bearing cap and loosen it a few turns. Alternate loosening both bolts until you have removed them. Pull the main bearing cap off the crankshaft journal and inspect the bearing sleeve. The sleeve should not have any deep grooves, pits or marred discoloration.

    11

    Wipe the crankshaft journal and bearing cap off with a rag. Place a strip of plastigauge inside the bearing cap, according to the kit instructions. Place the bearing cap back over the crankshaft journal and screw the main bearing cap bolts in by hand. Refer to your owner's repair manual for the proper torque, in foot-pounds, required for the main bearings. Use a torque wrench to tighten the main cap bolts, but do so in increments, alternating between each bolt to get an even tightening pressure on the cap.

    12

    Loosen the main bearing cap bolts with a socket and pull the bearing cap off. Use the kit gauge to measure the crushed thickness of the plastigauge. Refer to your owner's manual for the proper thickness allowed, indicated in thousandths of a inch. Worn main bearings will show a lower-than-normal thickness reading and must be replaced.

    13

    Check all of your main bearings in this fashion, one at a time. Record all of the measurements and compare them with your specification limits. Replace any obviously worn bearings, or those that do not crush to the proper thickness according to the plastigauge kit procedure. Do not forget to re-torque the bearings' caps when reinstalling the old bearings or replacing them with new ones.