Senin, 31 Agustus 2009

How to Troubleshoot a 1991 Chevy 700R4 Transmission

How to Troubleshoot a 1991 Chevy 700R4 Transmission

Most 1991 Chevrolets come with a 700R4 transmission. It is helpful to learn how to troubleshoot this automatic overdrive transmission before you take the car to a mechanic to be assessed, so that you know what issues you will need to address with the mechanic. The process uses tools you can find at any local auto shop and can be performed in the comfort of your own driveway with about 30 minutes of your free time.

Instructions

    1

    Look at the level of the transmission oil by pulling the handle on the transmission dipstick out of the transmission filler neck on the back side of the engine. Clean the dipstick off with a clean rag and return it to its original position in the filler neck. Recheck the fluid level, making sure it is between the highest and lowest marks on the dipstick. If the fluid is below or at the low mark, add more fluid using the funnel and the proper manufacturer-approved transmission fluid.

    2

    Smell the fluid and determine if a burnt smell is present. Burnt transmission fluid is a sign of internal transmission damage.

    3

    Turn on the vehicle's engine and place it in gear. Listen for a clunking sound. If you hear this, you may need a professional mechanic to replace the mounts on the transmission. This can happen with older vehicles with more mileage on them.

    4

    Drive the vehicle and listen to the revving of the engine. If you have a high revving sound when you change gears from "Park" to "Drive," as you push down on the gas pedal to accelerate, or if you feel the transmission lag on changing gears, you could have internal transmission problems.

    5

    Check for a dark red fluid leak or a puddle underneath the vehicle to make sure that it is not not leaking transmission oil. Rear main seal transmission leaks are common in older model Chevys.

Are Warped Rotors Dangerous?

Are Warped Rotors Dangerous?

Brake rotors are subject to extraordinary stresses -- both thermal and mechanical. Brakes slow the vehicle through friction, by converting kinetic energy (rotational movement) into thermal energy; considering the amount of energy transfer involved here, it should come as no surprise that there are very few perfect rotors out there.

Slight Warpage

    Almost all rotors have a little bit of warpage or wavyness, known as "runout." Runout is the inevitable consequence of heating spinning metal rotors past 900 degrees and applying pressure to one side. Slight runout isn't dangerous as far as the car is concerned, but if left unchecked, it can cause brake fluid pressure fluctuations that can cause premature wear on slave cylinder seals and antilock brake pressure modulators.

Extreme Warpage

    Overheating doesn't warp the car's rotors -- uneven cooling does. If the brake discs cool faster in one area than in another, the metal in that area will contract and pull the hotter metal toward it. The result is a wavy and structurally-compromised rotor that cannot distribute load evenly and may end up cracking the next time it heats up. When the rotor cracks and shatters, centrifugal force will spin its pieces outward. The end result: Your rotor turns into a red-hot Claymore landmine.

How to Check a Pressure Drop Across a Filter

How to Check a Pressure Drop Across a Filter

Testing pressure on both sides of a fuel filter lets you know whether the fuel filter is clogged and needs to be replaced or whether the problem with your fuel system is elsewhere. Testing fuel pressure drop is one of the best ways to diagnose a fuel system problem. These tests require some special tools. Loan-a-tool programs at a local auto parts store may enable you to borrow these tools at little or no cost.

Instructions

    1

    Test the fuel pressure before the fuel pump by installing the pressure tester in line before the filter. Release the pressure in your fuel system following the instructions in your manual. Disconnect the inlet side of the filter and attach the pressure tester to that side of the filter. Attach the other end of the pressure tester to the fuel line. Depending on your vehicle, this step may require some adapters not included in your pressure testing kit. Obtain the adapters you need at your local auto parts store.

    2

    Perform static and running tests. Turn the key to the "On" position, but do not start the engine. Listen for the fuel pump and when it stops running, take the reading from the pressure tester. Ensure that the pressure tester fittings are secure and that no fuel is leaking from them. This will ensure accurate readings. Start the vehicle and check again for leaks. Note the pressure reading and turn off the vehicle.

    3

    Release the pressure in your fuel system again. Reconnect all fittings and install the fuel filter. Install the pressure tester in line before your engine's throttle body or attach it to the Schrader valve provided for fuel system testing. Check your vehicle manual for specific directions. Test the pressure with the key on and the engine off and compare the pressure reading to your initial reading before the filter. Test the pressure again with the vehicle running. Note the pressures as before.

    4

    Analyze your results. Consult your manual for the proper running and static pressures for your fuel system. Replace the fuel filter if the difference between the two pressure readings exceeded 4 psi. Still replace the filter if there was little difference between static pressures but a larger difference in running pressures.

Minggu, 30 Agustus 2009

Troubleshooting a BMW 330Ci

Troubleshooting issues with your BMW 330Ci can quickly become a guessing game if you can't perform an accurate diagnosis. Using the onboard diagnostic system, also known as OBD, you can scan your 330Ci's electronic system for fault codes, which can be decoded to reveal the points of failure in your 330Ci and ease the troubleshooting process. Code scanners are available at most auto parts stores and some stores will even perform the code scan for free.

Instructions

Instructions

    1

    Locate the OBD port in your 330Ci that is found below the steering wheel and above the foot-wells on the driver's side of the car. The port will be approximately two inches wide and will be marked with "OBD2' or "OBDII" to indicate that it is the diagnostic port.

    2

    Plug the code scanner into the OBD port, then turn your 330Ci's ignition to the accessories position or turn the engine on so that the electronics in the car are activated. Note any diagnostic codes that the code scanner displays when your 330Ci's electronic system is turned on.

    3

    Cross reference the diagnostic codes with your local BMW dealer, a licensed mechanic or by referencing a website such as the one listed in the Resources section of this article. When a component of your 330Ci fails, the onboard computer will output a unique error code for the failing component. This can help point you to the areas of your 330Ci that are failing and need repair.

    4

    Check the fuse box on your 330Ci for any blown fuses. You can identify a blown fuse by seeing if the metal link at the top of the fuse is disconnected and if there is a brown or grey soot-like material on the inside of the fuse. If you are experiencing electrical issues, a blown fuse could be the culprit. By following the gird on the fuse box panel, you can locate fuses for components such as headlights, stereo system and emissions. Replace fuses as necessary.

    5

    Check to see if your 330Ci has the appropriate oil level by opening the hood and locating the oil dipstick. Pull the dipstick out of the engine, wipe it clean, then reinsert it into the dip stick tube. Pull the stick out again and examine where the oil sits on the dip stick relative to oil level indicators marked on the dipstick itself. Add fluid as needed.

Sabtu, 29 Agustus 2009

How to Troubleshoot a 2000 Ford Taurus

How to Troubleshoot a 2000 Ford Taurus

The 2000 Ford Taurus has a V-6 engine, two valves for each cylinder and a multi-point fuel injection system. It gets nearly 17 miles-per-gallon of gas when on the highway. Troubleshooting Taurus engine problems begins with checking the battery, alternator and fuses. After checking these parts, pull any trouble codes stored in the engine's computer. These codes are created electronically when a malfunction occurs in the engine and act as a problem-log to help you identify the source of the trouble.

Instructions

Check the Sources of Electricity

    1

    Test the battery for power. Connect a volt meter to the battery posts with the engine off; attach the positive lead of the meter to the positive battery post, and the negative lead to the negative post. The battery's voltage should read between 12.3 and 12.8 volts.

    2

    Start the engine with the volt meter still attached to the battery posts. Check the meter again. This time the reading indicates the power in the alternator; it should show a reading of between 13.6 and 14.3 volts.

    3

    Pull the fuses and check them for breaks. The fuses are located under the dash near the steering column. A plastic fuse puller, resembling a pair of thick tweezers, should be inside the fuse panel. If not, purchase a puller from an auto parts store.

Pull the Trouble Codes

    4

    Locate the test port or Assembly Line Diagnostic Link (ALDL) under the dash on the driver's side. The port has 12-to-16 electrical ports.

    5

    Connect a diagnostic scanner to the ALDL. The 2000 Ford Taurus requires an OBD ll scanner. Turn the key "On" without cranking the engine and follow the questions on the scanner. Select the option to scan the computer for trouble codes.

    6

    Copy the codes as you see them on the scanner screen and check your owner's or repair manual for the code meanings.

Check Major Engine Components

    7

    Start the engine and take a look under the hood. Check for signs of loose or broken wires, connectors, belts and hoses. Flattened hoses compress and trap air. Loose wires can become improperly grounded during movement; broken hoses cause moving parts to fail.

    8

    Look for signs of corrosion or damage on the battery, alternator, radiator and water pump. Pull the spark plugs and check the ends for rust or corrosive buildup.

    9

    Check the dates regular maintenance was performed. Ensure the oil, transmission fluid and coolant has been changed according to schedule. Make sure the air, oil and fuel filters have been changed on time.

How to Erase Computer Codes From the 2005 Equinox

You have replaced the defective equipment on your Equinox that caused the "check engine" light to illuminate on your dashboard, but you notice that the light is still on. This means the code is still stored on the ECU (electronic control unit.) Once you drive the vehicle 50 miles and the car completes a successful diagnostic of your engine,the light should turn off on its own. But you can also turn it off by erasing the computer codes on your 2005 Equinox.

Instructions

    1

    Connect your OBDII code reader to the OBDII port located under the dashboard on the driver's side. The OBDII port is the interface between your code reader and the ECU.

    2

    Turn the Equinox's ignition to the auxiliary position. This means, turn the key until the dash lights illuminate but do not turn the engine on. This turns on the ECU, OBDII port and the code reader.

    3

    Select "Clear Codes" on the OBDII code reader. This removes the codes stored in the databank of the ECU.

    4

    Turn the ignition key to the "Off" position and unplug the OBDII code reader from the OBDII port.

How to Troubleshoot a 1999 Yukon Air Conditioner

The 1999 GMC Yukon came with a large, 5.7-liter V-8 engine that pushes out more than 255 horsepower. Generally, large V-8 engines give off a lot of heat. That heat eventually leaves the engine compartment and enters the cockpit through the air vents. This means you need to have a high-powered air conditioning system to cool everyone down during the summer months. If the air conditioning unit is not responding as it should, it is easy to diagnose the problem.

Instructions

    1

    Turn the Yukon on and turn the air conditioning unit on. If the compressor works, move on to Step 2. If the compressor does not turn on, it will need to be replaced. This is a repair that should be handled by a professional technician.

    2

    Connect the Yukon service fitting nozzle to the recharge air can and attach the hose to the end of the nozzle. Twist the nozzle's top to release a small amount of air and close it after a second. This will clear the hose of any extra air.

    3

    Open the Yukon's hood and turn the Yukon on. Put the air conditioning on "High" or "Max." Connect the recharge hose to the Yukon's air conditioning valve. The valve is found on the rear wall of the engine compartment. The valve cap will be blue. Open the service valve on the recharge can to shoot the recharge vapor into the Yukon's air conditioning unit. Stop when the hose gauge reads between 25 and 40 psi.

    4

    Allow the air conditioning to run on high for five minutes. This will test whether there is a leak. If the air stays cool for the entire time while the air conditioning unit is running, you more than likely just ran out of coolant.

    5

    Monitor the air conditioning on the 1999 Yukon for the next few months. If the air conditioning unit stops releasing cold air after only a few weeks or months of use, there is a leak. This means you will have to get the unit flushed or replaced.

Jumat, 28 Agustus 2009

How to Run a Compression Test on a 2002 Chevy Tracker

The Tracker started its somewhat storied history back in 1989 as the "no-frills" Geo Tracker, which was based off of the Suzuki Samurai. The Geo Tracker continued through 1997 and was picked up by Chevrolet after Geo folded in 1998. The 2002 Chevrolet Tracker, based off of the Suzuki Vitara, came standard with a 2.0-liter in-line four-cylinder engine or an optional 2.5-liter V-6 engine. Testing the compression on these engines allows you to see if there is a problem with the piston rings or valves.

Instructions

2.0-Liter

    1

    Open the Tracker's hood and disconnect the wires connecting to all four coil packs, by pressing the locking button and pulling the wiring harnesses from the coil packs.

    2

    Remove the bolt securing each of the coil packs and pull the packs from the engine. This prevents inadvertent ignition while testing the compression.

    3

    Remove one spark plug from the Tracker, using a ratchet and spark plug socket,.

    4

    Insert the compression tester into the hole where the spark plug was and hand-tighten it. Tighten the compression tester into the engine a bit more with a combination wrench -- only about a quarter-turn past hand-tight.

    5

    Turn the ignition key, as if you were starting the Tracker, and hold it for about 10 seconds while the starter turns the engine over. Turn the ignition to the "Off" position.

    6

    Check the psi indicated on the compression tester and make a note of this reading. Press the button on the tester to reset the gauge.

    7

    Remove the compression tester from the engine and place the spark plug back into the engine. Tighten the spark plug to 18 foot-pounds with a torque wrench and a socket.

    8

    Repeat Steps 3 through 7 on all four cylinders.

    9

    Compare the pressures in all four cylinders to the manufacturer's factory compression specification of 199 psi +/- 15 psi. If any of the cylinders have more than 15 psi less than the specification, that cylinder's compression is too low and the engine requires servicing.

2.5-liter

    10

    Open the Tracker's hood and remove the plastic coil covers on each of the valve covers, using a ratchet and socket.

    11

    Unplug the wires from all six coil packs -- three on each side of the engine. Loosen the bolt securing each of the coil packs to the engine and pull all of the coil packs from the Tracker.

    12

    Remove one spark plug from the engine with a ratchet and spark plug socket. Place the compression tester into the hole where the spark plug was and hand-tighten it. Use a combination wrench to turn the compression tester a quarter-turn past hand-tight.

    13

    Turn the Tracker's ignition, as you would when starting the vehicle, and hold it for about 10 seconds. Turn the ignition to the "Off" position.

    14

    Check the psi reading on the compression tester and make a note of it. Press the reset button on the tester to drop the gauge back to zero.

    15

    Remove the compression tester with a combination wrench and hand-tighten the spark plug back into the engine. Tighten the spark plug to 18 foot-pounds with a torque wrench and spark plug socket.

    16

    Repeat Steps 3 through 6 for all six of the 2.5-liter's cylinders.

    17

    Compare the compression measurements of all six cylinders to the manufacturer's specification of 199 to 227 psi, with an acceptable variance of 15 psi. If one or more cylinders is 183 psi or less, that cylinder's compression is too low and the engine requires service.

How to Troubleshoot the Electric Brakes on a Horse Trailer

How to Troubleshoot the Electric Brakes on a Horse Trailer

Troubleshooting a malfunctioning brake light on your horse trailer may seem like a daunting task to someone who is new to working with electrical circuits. Luckily, diagnosing the problem can be accomplished with just a few simple tools. Do not attempt to tow the trailer with a malfunctioning brake light, as this increases safety hazards to yourself, other drivers and your horses. Towing a trailer with a malfunctioning brake light is also illegal in most areas.

Instructions

    1

    Check the electrical connection between the horse trailer and the vehicle. Make sure that it is securely connected and not damaged. Use a 12 volt test light to test whether power is reaching the trailer connection.

    2

    Open the fuse box of the vehicle. Use the diagram on the fuse box to locate the fuses related to the towing lights. Replace the fuse if necessary.

    3

    Use a screwdriver to remove the lens from the malfunctioning light. Check to see if the bulb is burned out or broken. Replace with a new bulb, if necessary.

    4

    Use a 12 volt test light to probe the terminals in the bulb socket. Connect the ground clip of the test light to the frame of the trailer. Use the probe to test the connections. If the light illuminates, there is power reaching the bulb socket. If the light does not illuminate, there may be a short between the bulb socket, and the vehicle connector.

    5

    Replace the lens cover with a screwdriver. Make sure that the lens is aligned properly and tightened securely. Be careful not to tighten the screws too tightly, as you could cause damage to the lens.

Kamis, 27 Agustus 2009

The Signs of Bad Wheel Alignment

The Signs of Bad Wheel Alignment

Wheel alignment is the adjustment of a vehicle's wheels so that they travel straight and do not cause uneven wear. A vehicle's wheel alignment is adjusted per the manufacturer's specifications so that it handles as desired. According to David Crolla, author of "Automotive Engineering," through regular usage or after an accident, a vehicle's wheelbase may become misaligned and require a tuneup. By paying attention to how your vehicle handles, you can detect signs of bad wheel alignment.

Pulling

    According to Richard Stone and Jeffrey K. Ball, authors of "Automotive Engineering Fundamentals," pulling is the earliest and most common sign of bad wheel alignment. When you are driving down a straight and level road, your vehicle should drive straight without correction. If the vehicle turns slightly to either the right or the left, it is pulling. Pulling means that the wheels of the vehicle are misaligned and that you should take the car in for an alignment. The road can cause a slight pulling to either side as well; if the vehicle only pulls on one section of a road, the alignment is not likely an issue.

Uneven Tire Wear

    The tires of your vehicle should wear evenly across the tread if the alignment is correct. However, if the wheels are misaligned, one side of the tire tread will wear more than the other. Uneven tire wear is often minute at the early stages of bad wheel alignment. To detect uneven tread wear, park the vehicle on a flat, paved surface with the wheels pointing straight forward. If the tread is visibly shorter on either the inner or the outer rim of the tire, uneven tread wear is present. Uneven wear is a serious indicator of bad alignment; if your vehicle exhibits this, it needs to be serviced.

Misaligned Steering Wheel

    A vehicle's steering wheel should be level when the wheels are pointed straight. If the steering wheel is off-center, it could be a sign of bad wheel alignment. A vehicle's steering wheel should never tilt either counterclockwise or clockwise when the car is driving straight. If it does, the vehicle should be taken to a mechanic for servicing.

Signs & Symptoms of Poor Ground Connection in an Auto Battery

Signs & Symptoms of Poor Ground Connection in an Auto Battery

Your car's ground wire, also known as a "ground cable" or "ground strap," is perhaps the single most important wire in its entire electrical system. Think of the ground wire or cable as your electrical system's foundation, the bridge over which all electrical flow must tread. A bad ground connection will ruin your electrical system's day, which makes establishing a good one an extremely high-priority project.

No-Start Condition

    This is one of the more obvious signs of a bad ground, manifesting in much the same way as a loose battery cable or a dead battery. When you attempt to start your car, you may hear a single click or a rapid tapping; this is the sound of the starter's solenoid opening or closing, or the sound of the starter's Bendix drive moving. The solenoid requires a certain amount of voltage to operate; if the ground is bad, then the solenoid will function, but the starter motor will absorb all of the current flow and shut the solenoid off.

Dim or Flickering Lights

    You headlights will do the same thing as the starter, but will likely dim instead of dying outright. A constant bad ground -- resulting from a frayed or damaged cable -- will create resistance in the circuit, which will deprive the headlights of power and cause them to dim. This may or may not be the case with xenon arc HID headlights, where a drop in input voltage may fail to initiate the lighting arc altogether. A cable that is simply loose may cause the lights to flicker as the circuit gains and loses the ground.

Dead Battery

    A battery that refuses to take a charge is one sign of a bad ground. The ground is a major part of the battery's charging system, so assuming that you're getting proper voltage output from the alternator wire, and the battery isn't hashed, then you may be looking at a bad ground wire. If the ground wire is loose, then the alternator won't deliver its full power to the battery, particularly at idle.

Testing the Ground

    The simplest way to check for a bad ground is to run a continuity test between the battery and the chassis. Disconnect the negative battery cable and connect the probe ends of a digital multimeter -- set to read volts DC -- to the negative and positive battery terminals. Record the reading; you should get something in the neighborhood of 12.6 volts. Next, remove the DMM lead from the positive battery terminal and touch it to the terminal on the disconnected negative battery cable. Your DMM should read within about 0.5 volts of your battery with the key in the "Off" position. If you get a voltage reading of anything below 11.5 volts, start looking for a bad ground.

What Are the Signs That My Oxygen Sensor Is Bad in My Jeep?

What Are the Signs That My Oxygen Sensor Is Bad in My Jeep?

The oxygen sensor in a Jeep controls the flow of oxygen that goes into the engine. Controlling this air-to-fuel ratio makes the Jeep more fuel efficient and helps with the Jeep exhaust emissions. The exhaust system is where the oxygen sensor is located. The sensor monitors the exhaust emitting from the engine and determines if the gasoline running into the engine is too rich or too lean.

Fuel Efficiency

    One of the biggest signs that the oxygen sensor is bad in a Jeep is the fuel efficiency tremendously decreases. Most car owners do not notice a small change in the amount of miles that the Jeep gets per gallon, but when an oxygen sensor goes out or begins to fail, the Jeep uses a lot more gasoline. This fuel usage is so dramatic that the Jeep owner may notice the change. This dramatic change in fuel efficiency can also be caused by other problems, but the Jeep owner should take the vehicle to a dealership to determine the problem.

Stalling During Acceleration

    Another sign that the oxygen sensor is bad in a Jeep is when the owner accelerates the vehicle but it stalls or there is a loss of power. A bad oxygen sensor causes this problem because it has quit monitoring the richness or leanness of the fuel that creates overheating in the engine or prevents spark plugs from firing properly. The loss of power is commonly noticed during acceleration from a stop and the Jeep stalls or dies. This stalling or loss of power requires the oxygen sensor to be replaced.

Emission Control

    Every state has yearly inspections on vehicles or emissions control laws that prevent the use of automobiles that emit dangerous gases from the vehicle exhaust. The sign of a bad oxygen sensor in a Jeep can be determined by this inspection. The emissions test conducted during this inspection will tell the Jeep owner that the oxygen sensor is bad when there is a noticeable change in the dangerous gases emitted from the exhaust. The catalytic converter changes the dangerous gases into less dangerous gases such as carbon dioxide or water vapor, and the oxygen sensor monitors this emission. When the oxygen sensor is bad, the monitoring of the exhaust ceases and can cause the emission test to show higher than normal dangerous gas emissions.

Rabu, 26 Agustus 2009

Chrysler Fault Code P0441

Chrysler Fault Code P0441

For Chrysler and other vehicles manufactured after 1996, "P0441" is a powertrain code in on-board diagnostics. It corresponds with the code description "Evaporative Emission Control System Incorrect Purge Flow."

Meaning

    The code signifies that part of the Evaporative Emission Control (EVAP) system is not functioning properly. Unlike engine knocking, you cannot notice this problem while driving. The EVAP system monitors fuel fumes and other components. The engine burns these fumes, rather than let them escape the Chrysler; if the system cannot detect the fumes' purging, it will trigger this specific fault code.

Probable Causes

    Some of the hoses within the fuel system may be old, faulty and leaking. Canisters or lines within the EVAP system may have become damaged. The purge solenoid may not be working, and the purge connector my have corroded to an unacceptable level; other shorts or forms of resistance may have occurred within the EVAP system.

Possible Solutions

    For Chryslers, examine the leak detection pump, which may need replacing; the purge solenoid, vacuum switch and power-train control module (PCM) may need replacing as well. Inspect all the hoses, lines, and canisters within the EVAP system, as any of these may require repairs. Look for any general corrosion or restriction throughout the system.

How to Check the Fuel Pump on a S10

It is important on a Chevy S10 to have constant fuel pressure across the fuel injectors. The fuel pump on an S10 is located in the fuel tank. It has the ability to produce more volume and pressure than the engine requires. The fuel pressure must remain constant even when accelerating. The volume however, must increase as the rpm increases. A fuel pressure regulator located on the end of the fuel rail allows all overpressure situations to let the excess fuel return to the fuel tank.

Instructions

    1

    Check the fuel pump fuse in the fuse and relay box on the driver's side fenderwell if the truck will not start. Look under the lid of the fuse and relay box for the location of the fuel pump relay. Place your hand on the relay and have a helper cycle the ignition key on and off. You will be able to feel and hear the relay activate if it is working properly. If it is not working, replace the relay and try to start the truck. If the truck will not start with a working relay, proceed to the next step.

    2

    Remove the cap on the fuel pressure test point (Schrader valve, which looks like a tire valve) on the fuel rail, located on the intake manifold. Install the fuel pressure tester on the Schrader valve by threading it on. Cycle the key on and off three times and observe the gauge. There should be 40+ pounds of pressure. If there is pressure the problem is elsewhere. If there is no pressure proceed to the next step.

    3

    Remove the air intake duct -- the big, black, plastic air pipe -- to the throttle body (located on the manifold) using a screwdriver. Hold the throttle open with the linkage on the right side of the throttle body and spray a one second shot of carburetor cleaner into the throttle body. Release the throttle linkage and try to start the truck. If it starts and runs for a few seconds, the fuel pump is the only problem and needs to be replaced.

Selasa, 25 Agustus 2009

What Causes Uneven Spark Plug Wear?

What Causes Uneven Spark Plug Wear?

Modern spark plugs are more durable than most previous designs. Until recently, spark plugs rarely lasted beyond a few thousand miles, and chains of tune-up shops thrived by offering this vital service. Professional technicians and astute hobbyists inspect spark plugs to gauge engine and ignition system conditions. The appearance of the business end of any spark plug may often reveal a discrepancy in that particular cylinder. The clues proffered by the condition and wear pattern of the plug electrodes often help diagnose symptoms ranging from improper ignition timing to poor driving habits. Accurately reading your spark plugs can render more valuable information than tea leaves or palm readers have ever disclosed.

Wear and Tear

    Normal wear of a spark plug is exhibited by some erosion of the center electrode. The square-cut shoulders of the electrode get rounded off, and the side, or ground, electrode may display some loss of material as well. The plug gap is widened by this normal loss of material, and engine performance and fuel economy suffer. Uniform wear on each plug may simply indicate needed maintenance, but pronounced wear of a single plug can signify a lean fuel mixture in that cylinder. A vacuum leak may be suspected in such cases. In instances where the center electrode wear pattern mimics the curve of the side electrode, material loss is obvious. This one-sided depletion is normally found in smaller engines, due to the heavier work loads that they experience.

Running Hot

    A spark plug that is running too hot can wear unevenly and prematurely. Excess heat is shown by electrodes with erratic wear patterns that are free of ashes or other deposits. The white insulation of the electrode may even be blistered by the extreme heat load. Such conditions noted on all spark plugs can indicate overly advanced ignition timing or engine cooling system shortfalls. A single plug suffering this symptom may be due to a vacuum leak in that cylinder. A vacuum leak dilutes the fuel mixture with excessive air that increases internal temperatures and reduces the service lift of the spark plug. A plug with a cooler heat range may solve the problem, once proper ignition timing, fuel delivery and engine cooling is confirmed.

Hard Knocks

    Engine spark knock, or "ping," can usually be heard from inside the passenger compartment of a vehicle. Each knock is actually a premature detonation in a combustion chamber. Spark knock can be caused by a defective emission control device, incorrect ignition timing, excessive engine loads and poor fuel quality. Spark plugs that are subjected to detonations often exhibit fractures in the electrode insulation. Not only does the ill-timed explosion damage the plug insulation, but pistons may be ruined by debris or concussion. The minor inconvenience of down-shifting appropriately or buying quality fuel pales in comparison to dealing with catastrophic engine failure.

The Gap Index

    Uneven erosion can be eliminated by modern spark plug designs that incorporate multiple ground electrodes or superior metal alloys. However, engine builders and racing enthusiasts practice the art of spark plug indexing to stem one-sided wear and to take full advantage of cylinder designs and ignition system abilities. The plugs are installed in the cylinder head before it is attached to the engine block. This allows positioning of the electrode gap for optimum combustion and uniform wear. The plugs are shimmed to secure the alignment, and the cylinder head is installed. Despite the expense of premium, high-performance spark plugs, they remain a viable alternative to such complex procedures. Modern car engines enjoy greatly extended service intervals, but modified, or otherwise finicky, engines can benefit from periodic plug inspections, cleanings and adjustments.

1990 Honda Accord EXR Starting Problems

1990 Honda Accord EXR Starting Problems

The 1990 Honda Accord EXR has 12 recalls on the automobile, but none of these recalls deals with the starting problems reported by RepairPal.com and CarComplaints.com. Technical service bulletins (TSBs) are published by the manufacturer concerning engine problems being experienced by some owners of the Accord. The EXR designates the model style of the Honda Accord, but all Accord styles have the same ignition components that affect the starting problems experienced by some owners.

Distributor Problems

    RepairPal.com reports that the 1990 Honda Accord EXR can develop an oil leak that affects the distributor of the automobile. The distributor is the ignition component that routes the voltage into the spark plugs in order for the spark plugs to fire or ignite in the correct order. When oil leaks into the distributor, it affects the wiring of the distributor, preventing the correct amount of voltage to be sent to the spark plugs or even short-circuiting the distributor. This prevents the Accord from starting because the voltage from the battery cannot enter the engine. The oil leak is attributable to a leak developing in the head gasket. The distributor must be replaced, and the head gasket needs to be repaired to correct this starting problem.

Alternator Failure

    The 1990 Honda Accord EXR has a TSB published by the manufacturer concerning multiple alternator bearing failures. The alternator is the engine component that recharges the battery. When the bearing in the alternator fails, the alternator can burn out, preventing the battery from recharging. The battery will lose voltage and not provide enough energy to start the Honda. The only correction for this starting problem is to have the alternator replaced and the battery recharged before the Accord will start again. No specific reason is given by technicians at RepairPal.com for this alternator bearing failure.

EFI Relay Failure

    Reports from CarComplaints.com state that the 1990 Honda Accord EXR may not start due to a failing electronic fuel injection (EFI) relay. When the EFI relay fails, fuel cannot enter the fuel injection system of the Accord, and the automobile will not start because of lack of gasoline. An EFI is an electronic device that controls the amount of fuel which runs into the fuel injectors from the fuel pump. The EFI needs to be replaced in order for this starting problem to be corrected and allow the fuel pump to work correctly.

Senin, 24 Agustus 2009

How to Read Diagnostic Trouble Codes on a Jeep CJ7

How to Read Diagnostic Trouble Codes on a Jeep CJ7

The Jeep CJ7 was introduced in 1976 as a successor to the Jeep CJ5. Both were rugged, four-wheel drive jeeps handed down from the postwar era, when the vehicles that supplied the military with mobility during the war were turned into vehicles for the average consumer. The CJ7 and its predecessors were originally thought to be for the agricultural person but found success with a wide variety of buyers. If the "Check Engine" or "Power" light is illuminated on the dash of your CJ7, the computer has recorded a fault for you to retrieve.

Instructions

    1

    Park the CJ7 and turn off the engine. It's important to turn off the engine before initiating the trouble code diagnostics, otherwise it won't work.

    2

    Turn your key on and off rapidly in this order: "On, Off, On, Off, On." Complete the sequence within five seconds. Never crank the engine because cranking will interrupt the diagnostic sequence and you'll have to start over. End with the key "On," meaning all dash instruments and interior lights are working, but the engine is off.

    3

    Keep your eye on the "Power" or "Check Engine" light, located in the dash instrument cluster. The light will pulse two-digit codes. Each digit is separated by a slight pause, therefore Code 23 will pulse this way: "Flash, Flash, Pause, Flash, Flash, Flash." Different codes are separated by long pauses.

    4

    Write the codes down as they pulse from the dash light. Each code has a different meaning, indicating a unique problem discovered in the CJ7's engine. Consult your owner's manual for the meanings to the codes stored in your Jeep, or visit the Offroaders website (see References) for a comprehensive list.

    5

    Make a note of when Code 55 flashes. Code 55 indicates the end of the trouble code sequence, meaning there are no more codes stored in the computer.

The Symptoms of a Blown Strut

The Symptoms of a Blown Strut

Struts, commonly referred to McPherson or coil-over shocks, have the responsibility of keeping vehicle tires flat on the ground over all conditions. They also serve as dampening devices that control and lessen the transfer impact between the chassis and road. Struts provide comfort while driving over the road, assist in smooth and even cornering, reduce tire wear, maintain curb height and keep suspension parts from vibration and shock damage. A vehicle owner has several things to look for in finding a blown strut.

Excessive Bounce and Rebound

    Struts that have lost their ability to cushion and rebound will bounce noticeably on the affected wheel. Plac the vehicle in "Park" with the emergency brake set, and put your full weight on the bumper at the corner of the vehicle where you suspect a blown strut. Bounce up and down hard, then release your weight. If the vehicle rebounds more than one-and-a-half times, it indicates a bad strut cylinder or damaged strut piston rod.

Diving and Squatting

    Look for a bad strut when you suddenly and firmly apply the brakes. A bad front strut will nosedive the hood downward, particularly over the side of the vehicle that has a bad strut. During a quick, hard acceleration, look for the rear end of the vehicle to noticeably squat down or dip more than normal. A single blown strut on the rear end will dip down further than the other side.

Fluid Leakage

    Visually inspect the shock housing, which is inside the coil spring. Any visual signs of oil, or a gummy film, will indicate the strut cylinder has lost its hydraulic oil. The oil usually passes through a seal at either end of the shock but will appear in larger amounts on the bottom of the shock housing or in the coil spring mounting plate. The oil does not have to look fresh; it can look like a oily film covered with dust.

Body Lean

    A blown strut will allow the upper part of the vehicle body to lean during a cornering maneuver. This will be apparent on the rear or front of the vehicle. The affected side the vehicle will also be slower to retain its normal height once the turn has been completed, and it might affect the steering response, adding some extra load to the steering wheel response. The vehicle might also wobble a bit after recovering from a strong, tight turn.

Noises

    Struts that have lost their power to cushion the weight of a vehicle will emit a muffled or loud metallic clunk when the vehicle drives over potholes, deep dips or curbs. The clunking noise is actually the chassis contacting or bottoming out against the suspension parts or frame. The noise can originate from the front or rear of the vehicle, but will assuredly happen over rough road surfaces.

Tire Wear

    Blown struts lose their ability to keep downward pressure on the tire. When the tire rebounds upward, even after a small or medium-sized hole or bump, it does not return to the ground immediately. This lag time causes the tire tread to skip or scuff over the road's surface, especially at higher speeds, tearing out small cup-shaped depressions in the rubber. You can see these scalloped cups by examining the bottom of the tire tread. Such scalloping indicates a blown, or useless strut.

Structural damage

    A blown strut will show evidence of structural damage. During visual inspection, symptoms will include broken or missing strut tower plate nuts or bolts, a disconnected or broken upper or lower shock mount connection or a bent, broken or jammed coil-over spring. The cylinder piston shaft (shiny part) might also be noticeably bent, in relation to the shock housing. Attempting to firmly move the strut shock or coil-over spring by hand is usually enough to determine if the parts have broken or loosened.

Curb Height

    Use a tape measure to measure the distance from the top of each wheel well to the ground. The distance should be approximately the same for all the wheels, give or take 1/2 inch or so. If one of the measurements reads significantly less than the other wheels, it indicates the curb height has dropped due to a bad strut. Struts that have lost pressure will let the car sag at their location. If you have a low reading on both struts on the same axle, perform a rebound test to make sure the suspension has not been deliberately set lower for this axle. If both struts fail the rebound test or show signs of leaking, then both are defective.

Idling Problems on an Infiniti

Idling Problems on an Infiniti

Launched in 1989 by Nissan Motor Company of Japan, the Infinity brand of cars are designed to be a luxury version of the cars manufactured by Nissan. While the cars are known for the same level of quality that is associated with Nissan, they do from time to time suffer from an idling problem. Typically, the issue is either the engine is idling too high or too low.

Instructions

    1

    Remove and replace the fuel filter for your Infinity automobile. Internal combustion engines require the correct amount of fuel and air mixture in order for them to run properly. If the fuel filter is plugged, it may be restricting the correct amount of fuel from entering the engine, thus causing it to idle too low.

    2

    Add fuel injector cleaner to your gas tank. Infinity engines are fuel injected and these injectors can become slightly plugged or "gummed" up over time. Using a fuel additive designed to remove this blockage should improve the idling of your Infinity.

    3

    Replace the "Idle Air Control Valve" on your Infinity car. Before you do this, you should have the vehicle inspected on a mechanics diagnostic scope. The "Idle Air Control Valve" is an electronic device designed to control the amount of air that is circulating in the engine. If it is not working correctly the engine may idle at low RPM's (revolution per minute) or very high RPM's. When you change the valve, inspect the wiring harness that plugs into it. Look for any indication of an electrical short.

Minggu, 23 Agustus 2009

EGR Valve Symptoms in an Altima

The Nissan Altima uses a digital electronic exhaust gas recirculation, or EGR, valve as part of its emissions system. The valve works to reduce harmful gas emissions due to fuel combustion and also lowers temperatures inside the engine for more efficient fuel burning. When this valve malfunctions, its symptoms can mimic several other common conditions, like air leaks.

Rough Idle/ Stalling

    If the EGR valve in the Altima is stuck in its open position it may cause the vehicle's engine to run rough when idling. The vehicle may also stall out due to spent emissions flowing back into the engine from the vehicle's exhaust system. These symptoms are often interpreted as a vacuum leak according to AA1Car, an automotive repair website. The Altima's electronic control module should emit a fault code that corresponds to the EGR valve. A digital diagnostic tool can be used to read the fault code and determine if the problem is caused by a vacuum leak or the EGR valve.

Spark Knock

    Spark knock is a rattling or metallic pinging noise that comes from an engine when it is accelerating or under strenuous activity. This means the fuel entering your engine is actually exploding instead of burning evenly. An EGR valve that is corroded shut can cause this condition in a Nissan Altima. The closed valve allows combustion temperatures within the engine to rise, which leads to the spark knock condition. Spark knock can cause failure of the engine's head gasket and damage to pistons and bearings.

Hesitation and Misfiring

    A damaged digital EGR valve, like those used in modern Nissan Altimas, may cause the engine to hesitate during acceleration. Hesitation is caused by the mismanagement of airflow entering the engine and exhaust gas leaving the engine. The damaged valve can also cause the engine to misfire due to premature combustion. This condition is similar to spark knock, though less severe. Hesitation and engine misfire may be misinterpreted as a vacuum leak in a similar manner as rough idling and engine stalling.

How to Troubleshoot the Jeep Grand Cherokee's Cooling Fan

The cooling fan in a Jeep Grand Cherokee keeps engine temperatures at the correct level by kicking on during times when the engine reaches higher-than-average temperatures. Without it, the engine can reach dangerous temperatures and damage engine components. If the cooling fan stops working, most do-it-yourself mechanics can troubleshoot it in a few minutes and decide what component needs replaced.

Instructions

    1

    Open the driver's side door. Pull the cover from the fuse box on the end of the panel. Using the fuse diagram on the inside of the cover, locate the fuse for the cooling fan and remove it with needle-nose pliers. If the metal link inside the fuse is broken, replace the fuse. If the fuse link it not broken, re-install the fuse and cover.

    2

    Remove the cover for the power distribution block in the engine compartment, toward the firewall on the driver's side. Using the diagram on the inside of the distribution cover, locate the 40 Amp fuse. Pull the fuse with needle-nose pliers. If the metal link inside the fuse is broken, replace the fuse. If the fuse link is not broken, re-install the fuse and cover.

    3

    Unplug the electrical connector running to the fan motor, which is in the middle on the rear of the fan shroud.

    4

    Attach a fused jumper wire to the terminal on the cooling fan that is more exposed after unplugging the electrical connector. Connect the other end of the jumper wire to the positive battery terminal. Attach another jumper wire to the other terminal, connecting it to the negative battery terminal. If the fan does not operate, continue troubleshooting.

    5

    Switch the wires to the opposite terminals. If the fan still does not operate, the cooling fan motor and assembly must be replaced. If the fan does operate, the vehicle must be taken into a professional service center for testing on the PCM, which controls the cooling fan relays.

How to Test a Weak Coil on a Blazer

It is important to have a high-Kv spark to ignite the fuel sufficiently to maximize the burn time. The higher the Kv (kilovolts) and the longer the duration of the spark, the more complete the burn. A weak coil will provide enough spark to operate the engine at low to moderate rpm under very little load. It will have problems at cruise, causing a misfire, because today's engines are designed for mileage. The only way to accomplish this is to lean the mixture. A rich mixture produces a conductive environment in the cylinder because fuel conducts electricity, which requires less Kv to ignite. Maintaining a spark in a lean environment requires much more Kv to jump the spark plug gap. A weak coil will be unable to maintain a spark under these circumstances.

Instructions

    1

    Pull the coil wire out of the distributor cap. Place the spare spark plug in the end of the coil wire and lay the plug on a good ground. Attach the jumper wire to the negative terminal on the coil. Turn the ignition key to the on position with the engine off.

    2

    Momentarily touch the jumper wire to the negative terminal on the battery and watch the spark plug for spark. Every time you touch the jumper wire to the negative terminal the plug will spark. A good spark will be very visible and blue in color. When the spark is barely visible and yellow it is definitely weak. Always check the coil at the coil wire first. A bad plug wire will give the impression the coil is weak. If the coil is tested at the coil wire first and found to be good, you know the plug wire is bad if the spark is weak there.

    3

    Pull the spark plug out and insert the spark Kv tool. Notice on the small tool that there are markings on the side on the tool indicating Kv voltage. Start with a low Kv such as 20,000 Kv and move the cone further away each time until the coil is unable to jump the gap, and you have the amount of Kv the coil is putting out. To move the cone, just unscrew the threaded shaft counterclockwise and the cone will move away from the bottom cone, effectively widening the gap --- simple but effective.

    4

    Check the coil wire if there is no spark or a very weak spark, to make sure the wire is not the problem. Place the volt/ohmmeter on the ohms scale. Remove the wire from the coil and probe both ends of the coil wire with the ohmmeter leads. The wire should have good continuity where the ohmmeter registers no more than 18,000 ohms. If there is no continuity or very high resistance, this is the problem. Replace the coil wire. If the wire is good, replace the coil.

How to Diagnose Bad Piston Rings

How to Diagnose Bad Piston Rings

Piston rings are an integral element of the internal combustion engine that provide a tight seal between the piston and the cylinder. Over time, piston rings can lose some of their tension, lessening the seal they form to the cylinder wall and decreasing the amount of compression created during combustion. This will result in a decease in output power, increased fuel consumption and can possibly lead to larger problem if scoring occurs on the cylinder wall. Testing the seal your rings make is easy with the right tools.

Instructions

    1

    Run the engine for a few minutes to warm it up; the warmer the piston rings are, the better seal they will make against the cylinder wall.

    2

    Remove the spark plug to the cylinder and piston you wish to test.

    3

    Insert the compression gauge adapter into the spark plug hole and torque to the specified weight recommended by the gauge manufacturer.

    4

    Attach the gauge to the spark plug adapter.

    5

    Disconnect the ignition coil to prevent the engine from firing.

    6

    Run the starter motor for a few seconds with the throttle pedal all the way down to obtain a maximum compression reading on the gauge. It would be advised to have a friend run the starter while you monitor the gauge to determine when the highest possible reading has been attained, and then tell them to turn off the car's ignition.

    7

    Compare the reading on the gauge to the vehicle manufacturer's recommended engine cylinder compression number. If lower than recommended, remove the spark plug adapter, and add a few drops of motor oil before replacing the adapter and running the test again. Adding a small amount of oil into the cylinder will help to create a better seal around a damaged ring, if the compression reading increases after adding some oil, it is a good sign that the piston rings are worn and should be replaced. If the compression gauge shows the same reading after adding the oil, the engine problem is more likely resulting from a valve seal problem or perhaps a blown head gasket.

Sabtu, 22 Agustus 2009

How to Troubleshoot a 2000 Hyundai Accent

How to Troubleshoot a 2000 Hyundai Accent

First released in 1994, the Hyundai Accent is a subcompact car that was still being manufactured and marketed by the Korean automaker in 2011. Troubleshooting the Hyundai Accent will vary depending on the type of problems you experiencing with the car. Troubleshooting will sometimes require the car being driven to see how it responds, and in some cases you will need to remove or test different parts of the car to see if they are performing as they should.

Instructions

    1

    Drive you Hyundai Accent to an empty parking lot at a nearby school or shopping mall. Drive the Accent and apply the brakes. Observe the steering wheel and brake pedal and see if there is a pulsing or vibrating feeling coming through either of the two. This can be an indication that the brake rotors are starting to wear unevenly. If this is not repaired, it could mean it will take longer for your Hyundai Accent to stop when applying the brakes. This should be looked at by a mechanic at as soon as you can get the car in.

    2

    Inspect the tires and look for signs of uneven tire wear. You do this both visually and using a tire depth measure and measuring the depth of the grooves across the tire. Check the air pressure in your tires to make sure they are inflated at the proper level. When driving the Accent, see if you have to turn the wheel to keep the car going straight. This and the uneven tire wear can be an indication that the alignment for the front wheels is out and needs to be repaired.

    3

    Open the hood to your Hyundai Accent, disconnect spark plug wires from the spark plugs and remove them from the engine using a spark plug wrench. Inspect the bottom of each spark plug and clean any black carbon off using a wire brush. If the ceramic housing is cracked, replace the old spark plugs with new ones.

How to Diagnose Disc Brake Problems

How to Diagnose Disc Brake Problems

Any brake component suspected of faulty operation needs to be inspected immediately. The front disc brake pads on newer vehicles have their own peculiar warning signs, and being able to read them early enough can reduce repair costs down the road. The front disc brake pads provide most of the stopping power for the vehicle and can actually wear out faster than the rear brakes. Disc brakes can show some early warning signs of failure if the vehicle owner knows what to look for.

Instructions

    1

    Check the dashboard for a brake warning indicator light. Faulty brakes will sometimes show up on your dashboard via a trouble code. Consult a trouble code book or an online resource to determine the type of brake malfunction involved. This type of warning light requires immediate attention.

    2

    Listen for any unusual sounds coming from the brakes under normal driving conditions. Disc brakes that have worn or become overheated make a variety of noises. When brake pads have overheated and become glazed, they will make a squeaking sound when they're applied, and this can be most noticeable during very slow stops. Disc brake pads that have worn past their lining limits will make a louder swishing, grinding or howling noise when the brakes are applied. This sound will be present at all times during braking, and sometimes a slight vibration can be felt in the steering wheel.

    3

    Shift the vehicle into park and set the emergency brake. Loosen the lug nuts on one wheel. Lift the vehicle in the air with a floor jack and secure it on two jack stands placed under the frame next to the front wheels. Finish removing the lug nuts, remove the wheel and set it aside. Carefully examine the pad thickness between the calipers. Make sure to inspect the inside pad since sometimes it wears out faster than the outer pad. Disc pads that have worn down to their rivets or have worn past factory specification limits must be replaced. Both inner and outer pads should be replaced on both front wheels, even if only one side has worn considerably.

    4

    Examine the disc rotor carefully. It should have a smooth, clean and shiny surface. There should be no striations or grooves in its surface. Deep grooves, sometimes appearing as parallel lines, will indicate that the rotor surface has made contact with the pad rivets, which shows excessive wear over a longer period of time. Deep grooves in the brake disc rotor can cause lockup and brake shimmy, accompanied by a loud grinding noise during hard braking. Disc rotors have a minimum thickness requirement and must be measured with a micrometer. Any grooved disc rotor must be removed and turned on a lathe or replaced if too much metal has worn away.

    5

    Inspect the brake caliper. The caliper holds the brake fluid that exerts pressure on the pads to grip the rotor. The piston inside drives the pressure, but it has seals to keep the fluid inside the caliper piston bore. Any brake fluid leak around the rubber boots inside the bore means that the seals have worn. Brake fluid will contaminate the pads, causing slippage, glazing and burning. Such a leak requires the calipers to be rebuilt or replaced if severely damaged.

Symptoms of a Weak Valve Spring With an Engine Surging at a High RPM

Symptoms of a Weak Valve Spring With an Engine Surging at a High RPM

Valve springs, as a whole, are underrated in terms of importance to the engine and priority where rebuilds are concerned. Valve springs are what keep the valvetrain dancing in tune to the camshaft, and they do wear out over time. The results vary from a mildly irritating surging to catastrophic failure depending on the mode and location of failure.

Valvespring Wear

    Valve springs are so simple that they don't seem like they should wear out, but they eventually go bad just like the springs in the suspension. The basic problem has to do with heat cycling and tempering. A metal's stiffness is a function of the shape of its crystalline matrix, which is a function of how the metal is cooled at the factory. When you cool very hot metal very quickly, you cause the crystals to seize up, which makes the metal very hard but brittle like glass. Getting the metal up to a lower temperature and slowly cooling it softens the material, making it easier to bend. A constantly bouncing spring builds up heat like a paperclip bent back and forth; after millions of heating-cooling cycles, the spring will re-temper and gradually lose its stiffness.

Valve Float

    As long as they don't snap a connecting rod first, all engines experience valve float at a certain rpm. Your engine's camshaft pushes its valves open via the lifters, pushrods, rocker arms or cam follower, depending on the design. The valves depend on those springs to push them back up, keeping the lifters or followers in contact with the cam. At high rpm, the valve's inertia overcomes the valve spring, keeping the valve open instead of pushing it up against the cam. Heavier valves float at a lower rpm because they have more inertia and fight harder to remain open; this is why high-end race engines often use valves made of a lightweight alloy, or employ hollow valve stems to reduce mass.

Multiple Valve Float

    This isn't uncommon on older engines. Valve springs, for the most part, are pretty much the same, and they wear out through heat cycling at approximately the same rate. Over time, the engine starts to lose power at high rpm, and its rpm limit drops as valve float becomes the determining factor. At that point, it may abruptly stop in rpm rise or may surge, depending upon the engine. While horsepower loss at high rpm isn't fun, it is a somewhat self-limiting thing. Once the valves start to hover off the seats by as little as 0.10 inch, the rpm rise stops and the valves don't rise any farther. This is a good thing; if rpm were to keep rising past the low valve-float point, the pistons might hit the valves and annihilate the motor.

High-RPM Backfire

    This isn't a phenomena unique to valve float, since it also can happen as a result of timing and fuel injection malfunctions. It is something to pay attention to, since it can precede a major failure. Backfires happen when valve float keep the valves open longer than than they should, allowing combustion gases to race out of the cylinder and into the intake manifold. Such backfires are more likely on carburated and throttle-body-injected engines than modern multipoint engines, because the MPI system doesn't inject fuel until after the combustion event. A weak exhaust valve can allow fuel to escape the cylinder and go into the exhaust manifold, resulting in an exhaust backfire.

Additional Problems

    A weak valve spring on a single cylinder could easily destroy your motor if it's an interference type motor -- where the pistons may hit the valves. Whereas an engine-wide valve spring failure limits rpm, failure of a single valve spring allows the motor to zing up to high rpm and float the bad valve until it hits the piston. On computer-controlled cars, a stuck exhaust valve and the subsequent excess exhaust fuel may overheat the converter, and triggers a check-engine light with codes for misfire and a rich reading from the oxygen sensor. A stuck intake valve will, at the very least, spike pressure in the intake manifold, confusing the manifold pressure sensor and throwing the computer into fits.

Jumat, 21 Agustus 2009

PT Cruiser Diagnostic Procedures

First put on the market in 1994, Chrysler designed the PT Cruiser as a retro-styled vehicle cross between a mini-van and an SUV. The vehicle became a hit for Chrysler so they continued to manufacturer the vehicle for years. Over the years, many issues have plagued the PT Cruiser and if you are a do-it-yourself owner, at some point or another you have likely wondered about the best PT Cruiser diagnostic procedures.

Manuals

    You can purchase service manuals from your local automotive part retailer that outline the processes from basic procedures to complete engine overhauls. Chilton Manuals, Haynes Manuals and the Chrysler PT Bench Manual are all options for the do-it-yourselfer. Each manual offers invaluable advise specific to your PT Cruiser. For example, the Haynes manual for a 2001 through 2009 PT Cruiser provides the processes for, tuning up and routine maintenance, engine overhaul procedures, cooling, heating and air-conditioning systems, fuel and exhaust systems, engine electrical systems, emissions control systems, brakes, suspension and steering systems and wiring diagrams.

OBD II Diagnostic

    All PT Crusier models use an OBD II (onboard diagnostic--second generation) to interface with the on-board computer. The OBDII monitors the sensors in your automobile and relays the information to the computer. When the OBDII locates an issue, it displays "Check Engine" on your dash panel. You can purchase a low-cost OBDII Diagnosis scanner and decipher the engine code being displayed by your OBDII. For years, this technology belonged to dealers and mechanics but now you can purchase your own OBDII scanner from most auto part suppliers. The OBDII scanner can save you a lot of time because it tells you the exact part to replace.

Recall and Complaint Websites

    If you are thrown off by a symptom your PT Cruiser displays and you are not quite sure where to go or you just want to know what could be coming down the road for you, check recall websites or complaint websites to gain a better understanding of what components on your PT Cruiser were recalled by the manufacturer and what components give other users the most problems.

How to Check the Engine in an Elantra

How to Check the Engine in an Elantra

An On-Board Diagnostic scanner can help check a Hyundai Elantra's engine. The service engine soon light does not need to be lit. The diagnostic system routinely monitors the engine for problems, and when a malfunction is sensed, the service light becomes active and a trouble code is issued. The Elantra's computer system, however, does not class every problem as trouble code worthy. The problem has to repeat itself a number of times. In the meantime, the system classes these faults as "pending." Retrieving pending codes is just as easy as pulling trouble codes.

Instructions

    1

    Consult your scanner's user manual for trouble code definitions. Mark the page the list begins, and set it on top of your Elantra's dashboard.

    2

    Insert the Elantra's key into the ignition, but leave the engine and the electrical system off.

    3

    Locate the Elantra's data link connector below the dashboard. It will be uncovered and to the left of the steering column. Plug your OBD-II scanner into this outlet. What to do next will depend on the exact OBD-II scanner you have purchased. The process is fundamentally similar across brands, but there are variations and differing button configurations. CarMD's scanner, for example, does not require you to start your engine, but others like Actron's CP9125 does.

    4

    Start the Elantra's engine if your scanner calls for it. Also, some scanners will activate themselves once a connection is sensed with a diagnostic scanner. Some scanners have to be manually switched on.

    5

    Look at the trouble codes displayed on your screen. Scroll through these and look for codes that are "pending."

    6

    Consult the manual you left on the dashboard for code descriptions. OBD-II codes are divided into two general classes. There are generic codes universal to all vehicles OBD-II compliant vehicles. There are also codes that are particular to Hyundai vehicles. If you manual does not contain these codes, you will have to go online and find the codes at a non-Hyundai related website. If your scanner's manual does not contain the codes at all, it may be because it comes with a software package that needs to be installed on your home computer. These type of programs are meant to assist in vehicle diagnostics.

    7

    Turn the car off and disconnect the scanner from the data link connection. Use the code definitions to troubleshoot the engine. If the problems sound more advanced then your experience or skill level, consider driving the Elantra to a Hyundai approved mechanic.

How to Diagnose Diesel Engine Turbo Chargers

There are numerous problems that can develop with your diesel engine's turbo system. Small issues such as boost pressure leaks can lead to more complicated malfunctions if not diagnosed and repaired immediately. Luckily, modern turbo diesel engines feature an extensive airflow and emissions monitoring system. The engine control unit (ECU) constantly monitors engine parameters such as air intake, fuel delivery, and exhaust emissions. Any problem that arises throughout the turbo system generally will trigger an ECU error code, which will trigger the dashboard "Check Engine" light. Most other turbocharger issues can be diagnosed by ear under normal vehicle operation.

Instructions

    1

    Plug an ECU error code reader into your vehicle's ECU access port. Generally, this port is located in the interior driver's side footwell area. If you do not have an ECU code reader, many automotive parts and service retailers offer free error code reading services.

    2

    Run the ECU error code reader program. This will give you a readout of any current error codes recorded by the ECU. Error codes also feature a brief description of the malfunction and/or affected engine parts, which makes for a quick and simple diagnosis.

    3

    Drive your vehicle to a roadway on which you can safely and legally accelerate the engine to its rpm redline. Accelerate the engine under full throttle and listen closely to the turbocharger noise. Excessive turbo whining indicates worn turbocharger internals, such as the turbo shaft or ball bearings. In more extreme cases, a grinding noise may be present when the turbo spools. This is due to the turbo compressor wheel or other internals grinding against the turbo housing.

    4

    Monitor the turbo boost pressure gauge during acceleration if your vehicle is equipped with one. A boost pressure gauge gives you a constant readout of the turbocharger's air output. If the boost value is inconsistent under acceleration, this indicates an air pressure leak somewhere in the turbo system. If the boost value spikes briefly upon acceleration, this indicates a worn or improperly set actuator, such as the actuator found on the turbo waste-gate or blow-off valve.

    5

    Open the hood of your vehicle and visually inspect the various turbo system components. Most turbo systems feature various rubber vacuum lines. These lines are prone to work loose or crack over time, which allows for a boost pressure leak. Replace any damaged vacuum lines immediately. Also, check all of the various connections throughout the intercooler piping system, which connects the turbocharger to the engine throttle body. Intercooler piping systems feature various rubber adapter connections. Ensure that all of these adapters are tightly secured and free of damage.

Kamis, 20 Agustus 2009

What Causes a Jeep PCM Failure?

What Causes a Jeep PCM Failure?

The Powertrain Control Module (PCM) in your Jeep is designed to serve as the brain of your vehicle's engine. The PCM is what is often referred to as your Jeep's "computer." It controls a variety of functions, including how your engine runs and the individual sensors that provide it with information. If your Jeep's PCM fails, you can expect your vehicle to exhibit a variety of symptoms, including the Jeep running badly, error lights appearing on the dashboard and a fairly wide assortment of electrical problems. Fortunately, problems with operation of the PCM unit can be traced to a few known causes.

Voltage Overload

    If a short occurs in your vehicle's power supply or wiring, or if your vehicle is somehow shocked, your Jeep's PCM may not recover from the jolt. Too much electricity will effectively fry your Jeep's PCM. According to AA1Car, this is commonly caused by a problem with either the solenoid or the actuator circuit.

Environmental Factors

    Environmental factors such as corrosion, thermal stress and vibrations can play a part in the failure of your PCM. Also, if you like to take your Jeep off-road, be aware that submerging the PCM in water or mud can lead to its sudden failure.

Faulty Equipment

    As with any vehicle part or mechanical item, a faulty PCM is occasionally manufactured. If you happen to be one of the unlucky few who gets a faulty PCM, which may be the case if you own a relatively new Jeep that has not suffered any damage, you will have to replace it. Fortunately, doing so may be covered under your warranty.

Rabu, 19 Agustus 2009

How to Recognize a Bad Ball Joint

How to Recognize a Bad Ball Joint

The ball joint in your car connects your steering wheel to your wheels so you can turn the vehicle left and right. When your ball joint is worn or torn, it can cause several problems for your car. There are plenty of signs that you have a bad ball joint. If you notice that anything is wrong, have the ball joint replaced before it causes even more damage.

Instructions

    1

    Listen for a loud cranking or popping sound as you turn your steering wheel. It usually means your ball joint is severely worn and your tire is becoming loosened.

    2

    Check for any shaking in the steering wheel. When your ball joint is bad, it will cause your tires and the suspension to bounce back and fourth. If the ball joint gets worse, it might cause the whole front end of the car to shake.

    3

    Move your front tires back and fourth when your car is parked. If there is a problem with the ball joint, your tires will wiggle and feel loose.

    4

    Check the handling of your car when you steer. A bad ball joint causes your tires to loosen up, which in turn causes severe handling problems.

    5

    Inspect your tires and look for abnormal wear. Problems with the suspension or ball joints will create uneven wear and scalloping on the tires.

Mac Tools Et1005a Specifications

Mac Tools was established by seven businessmen in the state of Ohio in 1938 and was first known as the Mechanics Tool and Forge Company. It currently has a product line that includes over 42,000 products, which are distributed through their worldwide sales force. Mac Tools sells hand and power tools, accessories, storage items and other products. It also offers diagnostic and testing equipment, including the Mac Tools Perceptor OBD Et1005A.

Compatibility

    The scan tool is compatible with General Motor, Chrysler and Ford automobiles that are equipped with an On-Board Diagnostic (OBD) computer. This computer system was built into vehicles that were manufactured after 1996. OBD computers monitor major components, such as engines and emissions control. Malfunctions in these components are indicated by a light in the vehicle's dashboard and are categorized into codes. The scanner retrieves, reads and interprets the code so necessary repairs can be made. The Et1005a will also retrieve all generic trouble codes on OBD-compliant foreign or domestic vehicles manufactured after 1996. The scanner has the capability to pick up special codes for a limited number of Asian and European vehicles

Computer Function

    The Et1005A can upload any data that is received into a personal computer. This data can then be printed. Menu-driven software is used to navigate the system. Trouble code definitions are pre-programmed into the scanner. It is fully upgradeable and will support newer vehicles using built-in flash programming. Freeze-frame data can be viewed using the 128 by 68 inch backlit screen with adjustable contrast.

Coding Specifications

    The scanner has the capability to read difficult codes and code erasure as needed. The potential code feature of the scanner notifies the mechanic of possible future problems with the vehicle. All data regarding each code is displayed, so the mechanic does not need a vehicle manual. You can research causes for the Malfunction Indicator Light (MIL) indicator and reset it.

Ford 4.6 EGR Valve Problems

Ford 4.6 EGR Valve Problems

The Ford 4.6-liter engine has been used in a variety of Ford, Lincoln and Mercury models since 1991. All versions are equipped with an exhaust gas recirculation (EGR) system to improve vehicle emissions.

EGR System Components

    Your EGR system is comprised of several components. The EGR valve controls the flow of exhaust gas into your intake manifold. The EGR vacuum solenoid (EGR SV) controls the flow of engine vacuum. The differential pressure sensor (DPFE) monitors the EGR flow and reports to your EGR modulator, which controls your vacuum solenoid.

EGR Valve Problems

    EGR valves contain a spring-actuated diaphragm. A common problem is a rupture or leak in the diaphragm. Check the function of your valve by revving the engine to around 2,000 rpm. If the valve stem does not move, the valve may be faulty. Clean the unit and test again. If faulty, the valve will need to be replaced.

Other EGR Problems

    Ford EGR systems are known for faulty DPFEs. A bad sensor will illuminate the check engine light and trigger any of the following fault codes: P0171, P0174 and P0401. This unit is far more likely to fail than your EGR valve. Additionally, lack of vacuum pressure may indicate a clogged vacuum line or faulty solenoid.

Selasa, 18 Agustus 2009

How to Troubleshoot RPM on a Chevy Blazer

The Chevy Blazer was General Motor's first real sport utility vehicle (SUV) that was based on the C/K truck platform. It proved to be very popular due to its ease of repair and cheap parts since C/K based truck components could be interchanged with the Chevy Blazer. However the Chevy Blazer could develop a number of problems over time that could be responsible for abnormal RPMs. A faulty engine control unit (ECU) or an overheating engine would be the most likely culprit.

Instructions

    1

    Pop the hood open on the Chevy Blazer by pulling the hood release latch in the cabin and then propping it up with a hood prop stick. Inspect the radiator first for any damage or debris on the heat sink. Remove any debris on the radiator that could be causing the engine to overheat and make the RPMs fluctuate. Consult your maintenance records for the last time the radiator fluid was changed and put in new fluid if it is time or if there has been a leak.

    2

    Inspect the battery for any damage or if it is dead. A malfunctioning battery could cause the engine to have a lower RPM if the spark plugs are not receiving enough current to supply a charge. Also inspect the alternator for any damage or corroded contacts that could also be supplying too little charge.

    3

    Turn the Chevy Blazer on and just let it idle. If the idle RPM is above 2000 RPM then the engine may be getting too much fuel and air in the carburetor. This could be from a stuck carburetor valve or a malfunctioning engine control unit (ECU). In either case it is best to take the Chevy Blazer into a dealership for repair. The ECU cannot be reflashed without dealership codes in some circumstances.

    4

    Shift the Chevy Blazer into Drive and give it a little gas. If the RPM suddenly surges then the throttle cables may be too tight and the engine "thinks" you are asking for more gas than you really are. If the RPM fails to go up then the cabling may be too loose and the inverse occurs.

Minggu, 16 Agustus 2009

1999 Chevrolet Cavalier Transmission Problems

Many of the transmission problems you may experience with your 1999 Chevrolet Cavalier can be diagnosed by recognizing the symptoms of the problem, such as noise and performance issues. This allows you to troubleshoot the malfunction without performing any mechanical inspection. Additionally, many transmission problems will activate the "check engine" light on the Cavalier's instrument panel. If this is the case, you can pinpoint the problem by hooking up a diagnostic reader to your Cavalier. The device will then give you a readout of the ECU error code recorded, as well as a brief description of the transmission problem and/or the parts that are affected.

Transmission Fluid

    Both automatic and manual transmissions use a special fluid to lubricate internal components. The transmission fluid should be replaced every 50,000 miles to ensure the transmission's continued performance. Additionally, you should periodically check the transmission fluid level via the dipstick located at the rear of the Cavalier's engine bay. If the fluid is worn or low, you may experience an excessive whining noise from the transmission, as well as rough shifting behavior and gear grinding. If the transmission fluid is low, Chevrolet suggests adding fluid by placing a long-neck funnel in the dipstick hole.

Internal Transmission Problems

    Automatic and manual transmissions both feature a complex system of interlinked gears that allow the transmission to vary the vehicle's speed. The gears also feature synchronizers that match the speed of opposing gears between shifts. If the gears or synchronizers are damaged, you may experience rough shifting behavior and/or grinding noises between gear changes. Alternatively, damaged internal shafts and bearings can cause shifting and grinding problems. The only way to pinpoint a problem with the internal components is by having the transmission disassembled and inspected, or by using an ECU diagnostic reader.

Automatic Transmissions

    The 1999 Chevrolet Cavalier automatic transmission features a torque converter that allows the engine power to be transferred to the transmission. The torque converter works by using a system of fluid-pumped turbines to convert the engine power into rotational force. If the torque converter is damaged, the transmission may not be able to properly engage, thus the engine will rev excessively, relative to the vehicle speed. Additionally, the torque converter features a lockup mechanism to improve fuel economy. If there are problems with the lockup mechanism disengagement, the engine may shudder or stall when you slow to a stop.

Manual Transmissions

    One of the most common problems with manual transmissions is a malfunctioning clutch mechanism. The clutch, which allows the transmission to connect and disconnect from the flywheel, is likely to wear out due to friction over time. When this occurs, the clutch mechanism will begin to slip. Symptoms of this include a strong burning smell under vehicle operation and excessive engine revving when the clutch pedal is slipped. Additionally, clutch chatter upon releasing the pedal indicates malfunctioning internal clutch components, such as a worn input shaft or clutch disc. Inconsistent clutch pedal pressure is often due to a damaged master or slave cylinder, which provides hydraulic pressure.

Ford 133 Code

An error code P0133 on your Ford vehicle indicates there is an issue with the air fuel ratio in the engine. While this error is unlikely to cause any drivability issues, it may cause problems with emissions testing.

Significance

    This error refers to the front oxygen sensor on the bank beside your engine's No. 1 cylinder. Seeing this error means the sensor is not adjusting the air fuel ratio, or not addressing it properly.

Causes

    An error P0133 can be reset on your Ford, and this may cause the error to disappear if it was only a temporary issue. If Error P0133 reappears after reset, your oxygen sensor could be failing. Other possibilities include problems with the wiring running to the sensor, a problem with the mass air flow sensor or an exhaust leak.

Considerations

    Before replacing the oxygen sensor on your Ford, check for inlet air leaks and exhaust leaks. Also, check the wiring to the oxygen sensor. In addition, the operation of both the mass air flow sensor and the oxygen sensor should be checked to determine which is the root of the error before replacing.

Sabtu, 15 Agustus 2009

How to Turn off the ABS Brake Lights on a 2001 Chevy Silverado

How to Turn off the ABS Brake Lights on a 2001 Chevy Silverado

Silverado was originally a trim level for the Chevrolet C/K-series trucks. The Silverado name replaced the C/K-series monikers altogether in 1999. The 2001 Silverado was available with a multitude of engines and drivetrains, from the base model 1500 to the 3500HD. The anti-lock brake system on the 2001 Silverado was responsible for monitoring all four wheels and the brake system. An ABS trouble light will appear on your dashboard if there is a malfunction in the ABS system.

Instructions

    1

    Open the driver's door of the Siilverado. Insert the OBDII scanner plug into the OBDII port under the dashboard. Turn the ignition key to the accessories position. Press the power button on the OBDII ABS-compatible scanner.

    2

    Select the ABS option from the main screen of the scanner, using the "Up" and "Down" arrow keys to make your selection. Press the "Read" or "Enter" button once you have made your selection. Select your vehicle year, make, and model in this same manner to tell the scanner what type of vehicle it is scanning. Press the "Read" button to scan the truck for ABS codes.

    3

    Repair the truck based upon the findings of the scanner. The repair could involve something as simple as an ABS sensor in the wheel well, or could be as involved as replacing the entire ABS control module.

    4

    Install the scanner back into the OBDII port of the Silverado after making the appropriate repairs. Go through the options in each menu to select ABS and then enter your vehicle specifics again. Press the "Erase" button on the scanner. The scanner will prompt you to make sure you want to erase the ABS code(s). Use the arrow keys to select your answer, and press "Erase" again.

Hyundai Accent Automatic Transmission Problems

The Hyundai Accent, a subcompact car available as a sedan and hatchback, was introduced in 1994. Edmunds.com contends that, although not glamorous, the Accent is a bargain-priced vehicle with a quality design and adequate performance.

Difficulty Shifting

    Hyundai Accent technical service bulletins (TBSs) report that the most commonly reported problem with an automatic transmission is irregular shifting. Reports indicate that shifting may be "difficult" or "harsh," especially when attempting to shift into drive or reverse.

Acceleration Failure

    TSBs state that multiple Accent models suffer transmission slippage during acceleration. Drivers may either experience failure to accelerate when shifting from 3rd to 4th gear or while accelerating from a stop. TSBs indicate that a failing transaxle may be the the primary cause of this slippage.

Recall

    In 1999, Hyundai issued a recall on 11,530 Hyundai Accent automatic transmissions, because of a defective pressure control solenoid. The defective part may result in transmission fluid leakage, which may affect the clutch, brakes and kick down servo. Contact your local Hyundai dealership to see if your 1999 Accent is on the recall list.

Jumat, 14 Agustus 2009

How to Test a Coil Pack on a 1989 Buick Lasabre

While Chevy's small-block has gotten the most attention, the Buick 231 V-6 has one of the most interesting success stories of all GM engines. This motor actually started out as an all-aluminum V-8, introduced in 1961, and sold to England's Rover Company in 1967. Rover used this V-8 to power all of its offerings for almost another four decades, while GM re-tooled the design as a V-6. The Buick 231 saw widespread use throughout the 1970s and 1980s, sprouting along the way turbochargers, fuel injection and multiple coil packs. Even today, GM's 3800 V-6 can trace its design roots back the multi-coil 3.8-liter, and to the odd, aluminum V-8 that GM didn't want.

Instructions

    1

    Identify all the parts of the coil pack.. There are two types. The Type One coil pack has electrode "towers" where the plug wires connect on both sides of the pack; the Type Two pack has the plug towers on the same side. The coil pack contains three separate coils arranged front to rear; each coil powers the plugs on two cylinders. The opposite-side towers on the T1 and the paired towers on the T2 connect to the same coil.

    2

    Unplug one of the plug wires from the a coil tower and connect your spark tester to it. A spark tester works just like a spark plug -- and, in fact, you can make one from an old spark plug and a plug wire. Connect the ground wire on your spark tester to the negative terminal on the battery. You may also connect the body of your test plug to the negative terminal with a jumper cable.

    3

    Start the engine and crank it up, if possible. Watch the spark tester; if you see a spark in the tester or the test plug, then turn the engine off and repeat the test with the other tower on that coil. That would be the opposite for a T1, adjacent for a T2. If you observe a spark from both towers on that coil, then that coil is likely functioning correctly. Reconnect the plug wires back and move to the next coil -- the center coil -- in line. Repeat with that coil, followed by the third coil.

    4

    Check the function of the coil pack, power supply and signal from the chassis, if you got no spark from any of the coils. Unplug the 14-pin harness connector from the coil pack and look at the connector; the terminals are marked with the letters A through P, skipping O. The crankshaft signal wire is G, seventh down from the top. The 10-volt signal is terminal N, or second up from the bottom.

    5

    Touch your multimeter's black (negative) probe to the battery's positive terminal, and touch the red probe to the "N" power terminal on the connector. Have an assistant try to start the car and observe the voltage reading on the DMM. It should read at or about 10 volts. If the voltage is less than, then you have a problem with the power voltssupply. Check the crankshaft signal, if the voltage is greater than 10 volts.

    6

    Connect the LED test light's ground clamp to the battery's negative terminal and touch its positive probe to the crankshaft signal wire or terminal G. Have an assistant attempt to start the car. Your LED light should quickly flicker on and off. If the light flickers, you've got power to the coil pack. Replace the entire, if the LED does not flicker at all.

How to Test a Fuel Pump Relay on a 2002 GMC Yukon Denali

How to Test a Fuel Pump Relay on a 2002 GMC Yukon Denali

The fuel system in the 2002 GMC Yukon has several electronic checking points. One of those checking points is the fuel pump relay. This relay opens the power circuit when the ignition is cut off, by releasing a switch. It closes the switch once the ignition is turned on to allow power to reach the pump. This relay can go bad in a few ways; so detailed testing is required to check for proper operation. However, the actual testing process is not difficult, it simply requires attention to detail.

Instructions

    1

    Pull the fuel pump relay from the fuse block by pulling upward with a slight wiggling motion. The fuel pump relay is the closest relay to the center of the box; view the relay map under the fuse box lid as a guide.

    2

    Read the circuit map on the top of the relay. Notice one side has a straight line with a small coil and one has a line that is broken. The straight line with the coil is the power side; the broken side is the switch side.

    3

    Turn the relay upside down, exposing the metal prongs. These prongs are in the same pattern as the circuit map on the top of the relay.

    4

    Connect one test wire to the positive terminal of the Yukon's battery, using the alligator clip; connect the other test wire to the negative terminal.

    5

    Connect the opposite ends of the test wires to the two prongs that match up with the power side of the circuit map, using the alligator clips. Listen for a faint clicking sound. The lack of a clicking sound means that the power circuit has too much resistance or the coil has failed. This means a new relay is required. If a clicking sound is heard, continue testing.

    6

    Place the third test wire on the positive battery terminal, using the alligator clip; connect the other end to either of the terminals on the switch side.

    7

    Turn the multimeter to 12-volt testing. Place the positive lead on the one remaining prong on the relay and the negative lead to the negative post on the Yukon's battery.

    8

    Read the voltage reading on the multimeter's screen, it should read approximately 12 volts. If the reading is less than 11 volts, the resistance is too high and the relay must be replaced.

Kamis, 13 Agustus 2009

2000 Dodge Neon Troubleshooting

2000 Dodge Neon Troubleshooting

The Dodge Neon was a compact, front wheel drive car manufactured by Chrysler between 1994 and 2005. The vehicle was originally put out to replace the Dodge Shadow, Plymouth Sundance, and Plymouth Duster. Mechanical problems with cars tend to arise over a sustained period of use, and dealing with them can be an intimidating proposition for car owners who aren't experienced in automotive maintenance and repair. However, a few basic troubleshooting procedures can help diagnose and fix issues with your 2000 Dodge Neon.

Instructions

    1

    Diagnose potential starting problems. A Neon whose engine cranks slowly could indicate a battery problem, even if the vehicle manages to start. An unaddressed battery issue could harm the alternator, so it should be dealt with promptly. Test it with a voltimeter. Also look for other signs of battery issues, like problems with brake and indicator lights.

    2

    Look for signs of electrical system malfunction. According to carcomplaints.com, electrical issues were the chief consumer complaint about the 2000 model. Symptoms of electrical malfunction include the inability to turn off the vehicle's lights, problems with the dashboard cluster, or computer system malfunction. Have the vehicle serviced by a mechanic.

    3

    Diagnose speed control issues. This has prompted recalls of the 2000 model. In cold conditions, vapors from the positive crankcase ventilation (PVC) system can freeze inside the throttle body, interfering with the vehicle's internal speed control capabilities.

    4

    Fix a vehicle that will not start. This can be as simple as a lack of gasoline in the tank or as complex as ignition coil failure. Other potential causes include fuel system malfunction, sensor issues, or a broken timing belt.

    5

    Correct a problem with vibration. If the Neon vibrates excessively while driving, it could be a symptom of one of several problems, including imbalanced tires, bent wheels, loose or worn drive shafts, damaged motor mounts, or even warped brake rotors. Rotate or replace the tires, and examine (and replace, if necessary) the drive shafts, motor mounts, and brake rotors. Let a professional mechanic perform the service if you're not qualified or underequipped for such advanced automotive procedures.