Selasa, 28 September 2010

2002 Mercury Cougar Sunroof Problems

2002 Mercury Cougar Sunroof Problems

Although many new cars come out without any defects at all, some models have issues that reveal themselves over time. While many people bought the 2002 Mercury Cougar, a handful of problems involving the vehicle's sunroof began to reveal themselves over the years. These sunroof problems can have several possible causes.

Electrical Problems

    Whether from fuses or from the signal not traveling from the button to the components moving the roof, in many cases the 2002 Mercury Cougar's sunroof won't open or, even worse, close, due to electrical issues. Though sometimes repairable with the replacement of a fuse, the problem may stem from the wiring itself.

Fitting Problems

    Many 2002 Mercury Cougar sunroofs fail because the pieces don't fit together correctly. The glass might be slightly too large or the rollers slightly small or tight---or both. the sunroof incorporate a combination of small moving parts, and having just one minor piece off can debilitate the entire mechanism. If the sunroof pieces don't fit together perfectly, it simply won't work.

Sticking Open

    Owners 2002 Cougars have reported sunroofs that stick open, allowing rain or snow to enter the vehicle and even damage the interior. Even without precipitation, cold wind blowing through an open sunroof can cause discomfort for drivers and passengers alike. Depending on the exact problem, you may require a professional mechanic to repair the sunroof and keep it from sticking.

Toyota Corolla Brake Troubleshooting

Toyota Corolla Brake Troubleshooting

The Toyota Corolla is a sedan first introduced in the United States in 1968. Troubleshooting a brake problem on your Corolla is similar to troubleshooting brake problems on other cars. Logic, deductive reasoning and mechanical knowledge must be used to pinpoint and fix the problem.

Considerations

    Familiarize yourself with the Corolla braking system for your model year. Consult the Corolla owner's manual or a general repair manual for specs. While the problems might be relatively similar between model years, parts will not likely be interchangeable.

Keeping Track

    Write down the problem that led you to troubleshoot your Corolla's brakes. Make note of any brake components you check, and rule them out as problems if they are functional. Systematically eliminate possibilities until you find the source of the issue.

Review the Common Problems

    Some common brake problems occur universally. Review common brake symptoms and their causes to facilitate repairs. For example, the reason a car pulls to one side when you brake is often the result of improper tire pressure, worn brake linings or front end misalignment.

How to Use a UV Dye for an Oil Leak

How to Use a UV Dye for an Oil Leak

If a car's engine is leaking, but the location of the leak is unknown, some mechanics will use an ultraviolet (UV) dye to help pinpoint the leak. The UV dye is designed to be compatible with the car's engine, and is put in place of the engine's oil. Once the UV dye has been run through the engine, a UV light is used underneath the vehicle to find the source of the leak. UV light reacts with UV dye, causing it to glow, so that it is immediately visible to the naked eye.

Instructions

    1

    Add oil-based UV dye to your car's engine in the prescribed ratio. The container for the dye will list the correct ratio.

    2

    Run your car's engine for a few minutes.

    3

    Park your car on level ground. Set the transmission in "Park." Set the parking brake. Use the car jack to lift the front of your car, making the engine underneath accessible. Place a jack stand under the car frame and use the car jack to lower the car onto the stand.

    4

    Climb underneath the car and turn on the UV light.

    5

    Shine the light on all parts of the engine's oil system to located a spot of glowing UV dye. The site at which the UV dye is found is usually next to the source of the leak. The color that the UV dye will glow depends on the brand you purchased.

Senin, 27 September 2010

My S10 2.8 Won't Start

My S10 2.8 Won't Start

Chevrolet S10 pickup trucks fail to start just as any other vehicle does. Causes for the S10 to not start can get complex and involved, yet some common signs can help diagnose the most common problem: a dead battery. Being able to diagnose the problem is great, but fixing the problem should be done by a professional mechanic or Chevy/GMC-certified dealer. Fixing car-related malfunctions, especially those involved with electronics, must be done by a professional for you and your vehicle's safety.

Instructions

Diagnosing a Dead or Weak Battery

    1

    Sit down in the driver's seat and turn the ignition key. Be sure the vehicle is in park. If your vehicle is a manual transmission, push the clutch in while you turn the ignition key.

    2

    Listen and observe immediately after turning the ignition key. If you hear a "clicking" sound repeatedly, you have a dead or weak battery. If power is displayed on the S10's dash but the car still won't start, you may have a bad alternator. If this is your problem, seek a professional mechanic as she is certified to diagnose and repair a bad alternator.

    3

    Remove the ignition key. You have no power to your vehicle and you need to jump-start the vehicle with power from an auxiliary power source.

Connecting Jumper Cables to Jump Start Your S10's Battery

    4

    Retrieve a secondary power source. Self-starting batteries are for sale that can be used to jump-start a vehicle, but the typical method is to use another vehicle with a good operating battery.

    5

    Park the second vehicle next to the S10. It's important to get as close as you can because some jumper cables can be short and difficult to attach to the batteries if the vehicles are too far apart.

    6

    Confirm both vehicles are powered down. Removing the ignition keys is the best way to be absolutely sure the secondary vehicle and your S10 are completely powered down.

    7

    Connect the red, positive ends of the jumper cable to the positive terminal on the secondary vehicle and your S10 vehicle. A "+" sign indicates positive on the battery. Clamp down the jumper cable with as much of the jumper cable's teeth as you can.

    8

    Connect the black, negative end of the jumper cable to the negative terminal on the secondary vehicle and connect the black end for your S10 to a piece of bare metal on or around the chassis. A "-" sign on the secondary vehicle indicates the negative terminal of the battery.

Powering up Your S10

    9

    Secure all four jumper cables ends. The ends must be fastened well so as not to slip off while you're powering your S10's battery.

    10

    Use the ignition key to turn on the secondary vehicle. Do not attempt to start your S10 vehicle.

    11

    Wait five minutes, then start your S10. Depending on how bad your battery is, allowing the battery to charge longer may be required. If that's the case, give yourself more time. If after several tries your S10 does not start, see a mechanic for a professional evaluation of the technical malfunction occurring in your S10.

    12

    Remove the jumper cables with extreme caution and in reverse fashion. Regardless if your S10 did or did not start, turn off the secondary vehicle and remove the ignition key before attempting to remove the jumper cables.

Alternator Test Procedures

Alternator Test Procedures

Alternators generate electric currents to charge your car battery while it is running. If your cars alternator fails, you will struggle to start the car within a few hours of the failure, as the battery will have run down. A faulty alternator will likely cause your cars "Check Engine" light to come on, and the headlights will appear dim when the engine is idling. Certain testing procedures will point out whether your alternator needs to be replaced, but these are best done by an auto technician.

Check for Physical Indications

    There are a few physical indications that signify a faulty alternator. Your cars battery warning light might illuminate randomly when the alternator brushes are worn out. When alternator bearings become dry, you will be able to hear a rough growling sound from the alternator case. Technicians sometimes use a common stethoscope to determine the source of the sound.

Testing Alternating Current

    In some cases a short or open-circuit failure can occur due to a diode fail. Alternating current voltage will leak into your cars electronic system, causing unpredictable problems with your cars on-board electronic systems. A multimeter is often connected to the battery and set to the AC voltage position to detect alternating current. With a normal, fully-charged battery the voltage will dip below 12.6 volts and quickly recuperate.

Testing the Battery

    Your cars battery should be tested as part of the alternator testing procedure. A battery with a bad cell will not achieve normal charging voltage, causing the alternator to over-charge the remaining cells and boil the electrolyte. Battery testing should be done by a trained technician, as a charging battery produces explosive hydrogen gas.

    A conductance tester is used to measure the electrical resistance in the battery, by applying a mild alternating current to battery terminals. Some technicians use load testers to discharge the battery at half its rated capacity. During this load test, the battery has to maintain at least 9.6 volts at its terminals after being discharged for less than 15 seconds.

Charging System Test

    Corrosion often increases electrical resistance of the ground circuit, causing the voltage regulator to sense less than the actual B+ voltage, resulting in overcharging of the battery. In older car models, technicians install an auxiliary ground wire from the regulator base to the alternator. The voltage regulator is then disconnected to accurately test the alternator only.

    With newer models, a professional scan tool is used to measure the charging voltage and retrieve any possible charging system errors. This scan tool can often be used to activate or control the field current to evaluate the alternators output.

Load-Test

    Conventional charging systems are often tested with an adjustable carbon pile tester. Battery discharge rate and the alternator charging rate are measured. This load-test will quickly indicate drive belt slippage on the alternator. Technicians should, however, be cautious not to overheat the alternator when testing it for maximum output.

How to Troubleshoot Tail-Light Turn Signals

How to Troubleshoot Tail-Light Turn Signals

Turn signals use simple electrical connections. The wiring comes from the car battery, is routed through the ignition switch and then onto the fuse panel. The fuse panel sends the electrical signal to the turn signal relay and finally to the lights. You rarely have a complex issue associated with malfunctioning turn signals. The main problems are burned-out bulbs, fuses or relays. Troubleshooting tail-light turn signals is a multiple-step process that takes about 10 minutes.

Instructions

    1

    Start the vehicle and activate the turn signals one at a time. Inspect the front and rear lights for both sides as you do. The front light on one side will flash rapidly while the rear signal does nothing when you have a burned-out bulb in the rear.

    2

    Remove the fuse for the turn signals and inspect the metal element in the fuse. The fuse panel will be located in the dash or in the engine. Consult your owner's manual for the specific location of the fuse box and the specific fuse that covers your turn signals. Replace any fuse that shows signs of corrosion, damage or burning.

    3

    Turn the signal on from left to right a few times. Feel the switch as you do and feel for the click of the switch catching. A damaged turn signal switch will feel loose or fail to stay active. Repeatedly turning the signal on and off will generate some activity, such as the turn signal activating for a brief moment or the signal lights flashing briefly, if the switch is broken or breaking. Replace the switch as necessary.

    4

    Activate your hazard lights. The turn signals may light up and not turn off or not turn on at all when the relay is damaged. The hazard lights usually have a separate relay. Replace the tail-light relay if the hazard lights activate properly but the turn signals fail to light up or flash on one or both sides of the vehicle. Consult your owner's manual to locate the relay. Some vehicles use the same relay for both hazard lights and turn signals. Replace the relay in that situation if the turn signal switch and hazard switch fail to turn on the signal lights.

    5

    Disconnect the wires from the socket to the turn signal light. The socket typically is screwed into the rear of the turn signal lamp. You access the socket through the trunk. Look for signs of burned contacts or corrosion. Clean with a wire brush and blow debris out of the socket. Reattach the socket and wires and check the function of the light. Have a mechanic replace the socket if excessive corrosion or damage is noted.

Sabtu, 25 September 2010

How to Troubleshoot Struts

How to Troubleshoot Struts

A smooth ride in your vehicle depends on many factors that work in concert with each other. The struts, also called McPherson struts, are one of the suspension's most important parts. The struts control the ride of the vehicle more than any other by absorbing sudden shocks, maintaining a constant vehicle height and keeping the tires flat on the pavement. Without the struts, the rest of the suspension parts would suffer from jolts and vibrations radiating up through the axles to the frame. Worn or failing struts have telltale symptoms that an observant vehicle owner can detect.

Instructions

Diagnosing Automobile Struts

    1

    Take the vehicle on a test drive. Find an area that has an irregular surface, like a parking lot that has speed bumps. Drive over the speed bumps at or below 5 mph and pay attention to the reaction of the vehicle's suspension. Harsh jolts or clanking noises will indicate that the struts (shocks) have lost their cushioning effect, which causes them to "bottom out", collapsing enough to allow the frame to make metal-to-metal contact.

    Note how well the ease of the steering wheel returns after you have made several sharp turns in a confined area. Watch for vehicle sway or leaning when making turns. Worn struts will allow excessive leaning. Apply the brakes suddenly a few times and look for the hood to dip sharply. If upon sudden acceleration, the hood raises up sharply, this indicates worn struts.

    2

    Park the vehicle and place the shift selector in park or neutral with the emergency brake set. Perform a rebound test by stepping up onto the front bumper, and using your weight, bounce the vehicle up and down (you can do this with the rear bumper too). After bouncing several times, step off the bumper and watch the front end. The front end should not continue rebounding more than one or two times. Worn shock struts and springs will allow multiple rebounds.

    3

    Inspect the condition of the front tire tread. Any cups or scalping in the rubber indicates the struts have worn to the point where they can no longer keep the tires firmly planted on the road's surface. Tires with cupping or scalping will appear as though a knife was used to carve out small sections of rubber--a definite indication the struts have failed. Check the rear tires, too. The rear tires might have been on the front axle at one time and rotated to the rear.

    4

    Use the floor jack to lift the vehicle up high enough to place it on jack stands--two at the rear and two at the front. Slide under the vehicle with a shop light. Examine the shock cartridges inside the springs. Look for any signs of oil running down the shock body, or a dirty, oily film on the lower half of the shock body. Such signs indicate the shock cartridge seals have broken and have lost their hydraulic fluid. Such shocks have lost all of their dampening strength and must be replaced.

    Look for any broken or loose mounting bolts and the top and bottom of the strut.

    5

    Make certain all four tires have the same pressure. Take a tape measure and extend it from the top of the fender wheel well to the ground's surface and record the inches. Measure all four fender wheel wells. Note that the front and rear measurement will deviate naturally because of the vehicle's design, but the side to side measurement should not deviate more than 1/2 inch. Struts that have unequal measurements have lost their ride height.

Saab 93 Heater Problems

Founded in 1937, Saab Automobile is a branch Saab AB, which is a Swedish aerospace and defense company. Despite its history of unique design and innovative safety features, Saab is not exempt from mechanical problems. In particular the Saab 900 and Saab 9000 suffer from several heater problems.

Heater Control Valve

    A common problem with the 1993 Saab 900 is the heater control valve, which is connected to the heater control levers in the car's interior. The main sign of a faulty heater control valve is not being able to turn the heat on or off. (Reference 2,3)

Heater Fan and Blower

    A common problem with the 1993 Saab 9000 is a faulty heater fan and blower resistor, which allows for airflow into the passenger's compartment for the heating system. An indicator of a heater fan/blower in need of replacement is a loud noise coming from the heating unit. (Reference 2,3)

Solution

    The cost to replace a heater control valve is about $222 for parts and labor. The cost of a new heater fan and blower resistor is approximately $392 for parts and labor as of February 2011. (Reference 2,3)

Jumat, 24 September 2010

How to Troubleshoot the Air Conditioning for a 1997 Geo Prizm

How to Troubleshoot the Air Conditioning for a 1997 Geo Prizm

Troubleshooting any mechanical problem is a systematic approach to trying to identify the problem, or the source of the problem. If the air conditioning is not working correctly in your 1997 Geo Prizm, there are a number of steps you can take to identify the cause of the problem and potentially fix it. Most states have laws regarding the re-capture and re-charging of automotive air conditioning systems, including those on the 1997 Geo Prizm. Check with you local mechanic about these regulations if you need to have your system re-charged.

Instructions

    1

    Turn on your 1997 Geo Prizm, and turn the air conditioning system on. When it starts to blow cold air, measure the temperature and how long the system maintains this temperature using your watch or stopwatch. If it only blows cold air for a short period of time, there may be moisture in the system that is causing the system to freeze up.

    2

    Remove the cover from the fuse box located under the dashboard on your 1997 Geo Prizm and look for blown fuses. If the air conditioning system doesn't turn on at all, look to see if the fuse needs to be replaced.

    3

    Turn the air conditioning system on and listen to the fan and for any other noises that are coming through the vents. This could be an indication that the fan or compressor motor is starting to fail on your 1997 Geo Prism.

    4

    Turn the car engine off and turn the key until the electrics, including the air conditioning, are running. Lift the hood to the engine compartment and inspect the system looking for leaks. Listen for larger leaks or using dish soap on the visible air conditioning lines. The dish soap will bubble if there is a leak in the hose when it is covered with dish soap.

Mercedes 450 Troubleshooting

The Mercedes Benz 450 sedan and coupe was the highest tier of the W116 platform made during the late '70s, early '80s. The 450 sedans were the predecessors to the S-class sedan, and the 450 moniker denotes it's 4.5 liter V-8, though it was also used on the 6.9 liter V-8 flagship model. All 450 models came with a three-speed automatic and a rear-wheel drive power train. These sedans and coupes were noted for their mechanical reliability though their electrical wiring can corrode with age.

Instructions

    1

    Pop the hood on the 450 and look at the spark plug wiring. The V-8 requires strong currents to spark the combustion chambers, and any corrosion in the wires can deprive the spark plugs of current. The intake manifold should be free of rust, as well as the carburetor on top. Look around the edge of the engine where the intake manifold meets the lower block for signs of oil leaks. The gasket could have gone bad or there could be micro fractures. If the engine is broken then consider an engine swap to something newer like a Chevy short block. Old Mercedes engines can be very expensive to repair.

    2

    Start the 450 up and listen for the engine to make any noises. The 4.5L Mercedes V-8s make a soothing rumble when running normally. Any banging or scrapping could indicate a broken camshaft or pistons. Shut the Mercedes Benz off immediately and call a mechanic if that happens. You will either have to rebuild the engine or swap it out.

    3

    Shift into drive and take the Mercedes Benz 450 for a test drive. If the throttle tip in feels too sudden then the carburetor may be malfunctioning, making the fuel air mix too rich. Look at the engine temperature as you cruise on the highway. If the engine temperature gets into the red band, then the radiator is damaged or the coolant lines are pinched somewhere. For longevity, it is best to equip older V-8s with auxiliary fans to keep them cool. The Mercedes Benz V-8 of the '70s was all steel, so it retained heat more than newer V-8s that have fast-cooling aluminum parts.

Kamis, 23 September 2010

I Have a Sticking Transmission

I Have a Sticking Transmission

Transmission issues are notorious for their cost and complication. Often, if car owners hear the word "transmission" from a mechanic's mouth, it's not a good sign. Understanding why a transmission sticks might help in repair cost or avoid the issue altogether. If your car already experiences a sticking transmission, it could be one of many problems related to both manual and automatic transmissions.

Scanning the Diagnostic Trouble Code

    On newer car models, a diagnostic trouble code designates certain problems in the transmission. For most cars, a "Check Engine Light" appears on the dash. The codes generate after plugging a code reader or scan tool into the vehicle's diagnostic connector. Auto repair shops have diagnostic code reader tools. Some auto parts stores do the scan for free and look up repair parts for you. This code is the first step to diagnosing your sticking transmission problem.

Sticking Automatic Transmissions

    Automatic transmissions involve more construction and so have more problems because of all the different parts. If the transmission experiences slipping or sticking in a certain gear, the problem could be low transmission fluid or a bad solenoid, which is a valve that controls the flow in and out of the automatic transmission based on an electrical current. If the sticking speed is higher than specifications, you likely have a sticking pressure regulator valve. Again, a diagnostic code isolates the problem, particularly in automatic transmissions.

Sticking Manual Transmission

    A major cause of sticking in manual transmissions is a broken shift cable. If your vehicle becomes hard to shift, it could mean a shift cable is failing. The problem starts as the shift cable does not pull on the linkage, and the gear shift becomes too stiff to operate. For this problem, replace the cable and study the linkage to make sure no damage occurred to the transmission. Another issue could be the clutch, especially if the gears grind or clash when shifting or the clutch is not fully releasing when the pedal is pushed back. You might need to replace the clutch in this instance.

Cold Weather Sticking Transmission

    In winter months, you might notice your transmission sticking more. The problem likely lies with the lubricant in manual transmissions. A heavy lubricant will not work in cold weather just as a thin lubricant will not work in hot weather. Vehicle manufacturers specify the type of lubricant needed for your vehicle's transmission. An oil level left too low for a long period of time can also contribute to a worsening condition of a manual transmission.

Does Disconnecting a Car Battery Clear the Computer?

As of 1996, all cars sold in the United States have come equipped with an on-board diagnostics computer system that retains error codes and engine settings in its memory. Some have the ability to retain the code up to several hours after disconnection from the battery, depending upon the vehicle model and computer capabilities. But in most vehicles, once the battery is disconnected, the car's computer memory clears. While this is an easy fix to get rid of codes, its not advisable unless you have corrected the problem with the vehicle first.

Settings Keeper

    Use a settings keeper that will save computer codes, radio settings and other settings normally lost when disconnecting the vehicles battery. Most of these small units plug in to the cigarette lighter or the optional 12-volt plug-in port on many vehicles. The unit will maintain the on-board diagnostic computer settings, radio settings, alarm theft deterrent settings and any other personal settings when you have to replace or complete maintenance on your battery and disconnect it from the vehicle.

Check Engine Light

    When you first start your vehicle, the check engine light flashes and then turns off after the engine engages. This is an indication the on-board diagnostics computer is functional and working. If the light comes on and doesnt go off, something in the system is indicating a problem. Sometimes this happens after disconnecting the battery; the computer needs to complete system checks and relearn the vehicle's operations. This may take several miles and a few trips to complete.

OBD Readiness Status Indicators

    All on-board diagnostic computers have an OBD readiness status indicator, which means the computer monitors sensors and conditions in the vehicle and delivers a "ready" that indicates all is well in certain systems. Depending on the model and vehicle manufacture date, the computer completes up to 12 checks. When testing emission, for example, the computer has a ready or not ready status. When the computers memory clears, it will take up to 50 miles and a few trips for the computer to complete all the checks and provide a ready status or throw an error code. Relearning the fuel values may take up to 500 miles, depending upon the vehicle. When the system is in "not ready" status, it will not pass the OBD-II part of the smog emissions tests.

Scan Tool

    If you want to find out what error codes are coming up with your computer, or need to verify why the check engine light comes on, rent or purchase an OBD-II scanner to check the codes and determine the problem. Some auto parts stores will also complete the check free. Its important to keep the settings in the computer so you can determine any vehicle problems. Disconnecting the battery to remove the settings isn't advised; it doesnt correct the problem and the codes will reset once the vehicle completes the necessary trips and miles for the on-board computer to deliver its diagnostics.

1989 Dodge Turbo Problems

In 1984, as a result of focusing on more fuel efficient four-cylinder engines, Dodge began to offer the turbocharged Daytona model. The 1989 Daytona was a performance coupe and, as such, sacrificed convenience features for speed and power.

Seating

    The 1989 Daytona was built on a 97-inch wheel base and was180 inches long; that was enough room to seat two passengers and their cargo. Although the Daytona was built with rear seats, the seats were small and did not seat adults comfortably. The seats could be folded down to make extra trunk room.

Turbocharger

    The turbocharger required more frequent maintenance than a naturally aspirated engine. Oil and filter changes must be performed more frequently because the engine shared oil with the turbocharger. The turbocharger itself had a shorter lifespan than the engine, and needed to be replaced or rebuilt to maintain proper function.

Turbo Lag

    The Daytona's turbocharger served the purpose of providing additional air to the engine and, as a result, increased the engine's horsepower. However, the turbocharger needed time to produce maximum rotations before it provided additional horsepower. When the gas pedal was pressed, there was a delay in engine response. The delay is often referred to as turbo lag.

Stalling in Cold Weather With a 1996 Dodge Ram

Model year 1996 was an important one, not just for the Ram, but for every other vehicle in America. This was the year that the Federal government mandated the adoption of Onboard Diagnostics, Series II protocol. Among other things, one of OBD-II's primary virtues is its ability to adapt to any environment while maintaining the appropriate timing and air/fuel ratio. But sensors do fail over time, causing computers like the one in the Ram to make mistakes and fail to adjust for changes in air temperature and density.

Coolant Temperature Sensor

    A failing coolant temperature sensonr is one of the primary culprits for cold-weather problems. Before the introduction of computer control systems, engines used choke plates to reduce airflow into the engine while cold. Cold engines don't want to burn fuel, so they need a richer mixture to maintain a consistent burn in the cylinders. If your coolant temperature sensor starts to go out, the engine may think that it's running warmer than it really is, and run rough or stall as a result. This will likely trigger trouble codes indicating an intermittent misfire, if not codes specific to the coolant temperature sensor.

MAP Sensor

    The Ram's engine control system relies primarily on readings from the manifold air pressure/vacuum sensor to determine load on the engine. It uses what is called "speed-density" calculation to account for how much oxygen is going into the cylinder, as opposed to the mass-airflow systems used by other manufacturers. Speed-density systems are very efficient, but they're also very restrictive. They work very well within certain ranges, but they're also very sensitive to sensor malfunctions and variations in air temperature and pressure. A bad manifold air pressure sensor will certainly cause the truck to malfunction when the air is colder and denser than it might otherwise be.

Intake Air Temperature Sensor

    The intake air temperature sensor is somewhat ancillary on a mass-flow system, but is absolutely vital on a speed-density system. The computer uses indexed information from the IAT and MAP, which it uses to calculate exactly how much oxygen is going into the cylinders. Without correct information from the IAT, which is essentially a thermometer, the computer is missing half of the information that it needs to calculate the correct air/fuel ratio. So, it assumes that your running at around 70 degrees, where the air is far less oxygen-dense than it is at 20 degrees. So, the engine winds up running far leaner than it should and will stall in colder climates or temperatures.

Transmission Temperature Sensor

    Your transmission also has a temperature sensor and its function is just as vital as that of the engine's coolant temperature sensor. Cold oil is thick oil, and thick oil doesn't want to flow through the transmission's fluid lines or the vanes in the torque converter. Your Ram's computer use information from the fluid temperature sensors to determine how far to open the valves in the transmission, when to open them and how much resistance to expect as the fluid tries to force its way through the torque converter vanes. It will, concordantly, increase power output to keep the engine running until the transmission fluid warms up. The speed-density system also helps to perform this function, but a bad transmission temp sensor can stall affect the engine in the same way.

Rabu, 22 September 2010

What Are the Causes of a Burned Up Piston in an Outboard Motor?

What Are the Causes of a Burned Up Piston in an Outboard Motor?

One of the major engine failures of an outboard motor concerns the temperature and operation of the piston. Responsible for compressing the air-fuel mixture, then forcing it from the exhaust, the piston can overheat and suffer catastrophic damage from a number of reasons. If a boat owner knows what can cause a burnt or galled piston, he can initiate a preventive maintenance procedure to stop it from happening.

Lean Fuel Mixture

    A common cause of overheated pistons relates to insufficient fuel delivery to the cylinder to keep the temperature down. Idle mixture screws that have settings which are too lean will cause a lean air/fuel mixture, and too much air in the combustion chamber causes the temperature to rise. Kinked fuel lines and clogged fuel filters will also starve the cylinders. A rich, or wetter mixture counteracts the condition.

Cooling

    When the cooling passages in an outboard motor become clogged, cooling water does not reach the major components, such as the power head, cylinders and block. Likely candidates for overheating include restricted or clogged freshwater inlet vents on the lower unit, a deformed or deteriorated water pump impeller and contaminated oil which has lost its lubricating qualities and viscosity.

Heat Range and Spark Plugs

    A spark plug that has an improper heat range will allow higher than normal cylinder combustion temperatures and cause localized overheating on the piston top. A too-narrow spark plug gap can also cause early spark fire and allow unburned fuel to turn into carbon deposits.

Oil

    Dirty oil -- oil which has lost it lubricating qualities and thickness -- will add friction to the rod and crank bearings, piston rings and pins and scoring on the cylinder walls, raising the piston temperature. Piston skirts suffer the most severe friction of scoring and galling, which can melt the piston and rings. Also, improperly mixed 2-cycle outboard oil that does not have the proper amount of lubricating oil will cause rapid overheating.

Pre-ignition

    Pre-ignition results from hot spots on top of the piston when carbon builds up in the combustion chamber. The carbon burns from an afterglow when the carbon has no time to cool down, which causes a premature firing and heats the piston top. An audible "pinging" sound can be heard during idle or low-speed throttle operation. Heavily carbonized exhaust valves allow carbon buildup, as well as excess cylinder pressure. A misaligned head gasket which allows a part of the gasket to overhang into the cylinder can also cause a hot spot.

Detonation

    Detonation results when the combustion chamber contains two opposing hot spots which fire at the same time. It causes a mini-explosion, keeping the piston hot all the time with no chance to cool between strokes. Detonation is heard by a loud spark knock, and the resulting un-timed explosions can burn a hole in the top of the piston.

Advanced Ignition Timing

    If the ignition timing is too far advanced, it causes an early spark which fails to burn the complete mixture of vaporized fuel in the combustion chamber. This results in rapid overheating, since the mixture is too lean to keep the combustion temperature down to normal limits.

Gas

    Old gas which has sat in a fuel tank for four months or more will cause the fuel to thicken with a gum and varnish, which will burn unevenly and poorly. The gum and varnish adheres to the cylinder walls and valve seats, causing an adhesion surface for carbon particles and unburned soot. Low octane fuel also causes uneven and incomplete combustion ignition, clogging the valves and allowing carbon buildup.

Signs of a Low Battery in An Auto

Reliable cars require diligent maintenance and awareness of changes in performance, which require unscheduled changes and replacements. A dying battery will usually give you notice of the need for a new battery before you need to call a tow truck.

Symptoms

    An easy indicator that your car's battery is weak and may need to be replaced is a clicking when the car is first started. This can indicate a problem with the starter, which relies on battery power to turn over. Other symptoms include the car lights being dimmer than normal or the voltmeter is below 12 volts.

Causes

    Car batteries are not meant to last forever and will need to be periodically replaced. Besides the shelf life of batteries, you may need a replacement during extreme weather shifts or if the car accessories have been left on without the motor running.

Solution

    Sometimes a car battery will need a jump from the battery of another car using jumper cables to restart the battery life. Other times the battery will need to be replaced. If you do it yourself, be sure to wash your hands to keep corrosive and dangerous chemicals from the battery from getting in your eyes or mouth.

Symptoms of an Intake Gasket Leak

Symptoms of an Intake Gasket Leak

Automobile engines work using a vacuum, or lack of air, to push and process fuel. Intake manifolds contain a smaller vacuum that directs fuel into the engine. The intake manifold has a gasket that can be prone to leakage. Leaky intake manifold gaskets can reduce vehicle performance and cause noise.

Visible Symptoms

    A vehicle with an intake gasket leak may show a decrease in coolant levels. Puddles of coolant may form underneath a vehicle with a gasket leak, depending on the severity of the leak. Coolant levels should be checked often to evaluate any leakage.

Audible Symptoms

    Intake manifolds use a vacuum to move fuel into the engine. If a leaky gasket is present, the introduction of air into the manifold can cause a whistling or sucking sound. This noise can be soft or loud, depending on the type of leak.

Performance Symptoms

    A leaky intake manifold gasket disrupts the introduction of fuel into the engine. It also adds air to the engine mixture which can lessen engine performance. Cars suffering from a leaky gasket may experience a rougher idle or stalling in severe cases. Misfiring cylinders and slow acceleration are also common symptoms of leaky manifold gaskets.

Selasa, 21 September 2010

Ways to Check Spark on Points

Ways to Check Spark on Points

For decades before electronic ignition became a more reliable form of triggering a combustion engine, condenser-point ignition systems operated as the standard, sometimes reliably and sometimes not so dependable. Today, most motorcycle and vehicle ignitions work on demand, running consistent ignitions that need no adjustment. However, if you ever have the joy of owning or working on a vintage vehicle, you will understand how important alignment of the points ignition is to obtaining a proper spark and combustion in an old engine.

Background

    The points-condenser ignition system first appeared in 1911 thanks to the work of Etienne Lenoir, who had invented the spark plug 50 years earlier. Due to Etienne's work, the first points ignition system began to appear in cars and vehicles, and the design was improved further by later designers and engineers as the system was relied on more and more. By the 1970s, electronic ignition was making a strong headway as the new ignition system to adopt, but motorcycles and scooters were still being produced with point systems as late as 1975.

Combustion and Spark

    A spark from a spark plug helps the combustion process but it does not represent the end-all, be-all of the process. In fact, the timing of when that spark occurs significantly impacts the performance of an engine for the better or worse. If the timing is off, the engine could run poorly or the combustion could pre-ignite before the piston is ready, causing internal damage and engine failure. With a points-condenser ignition, the points must be adjusted so that their connecting point occurs slightly before the piston reaches its further reach, known as top dead center. This allows the spark to build and fire just as the piston reaches full compression, utilizing the full energy of the combustion process.

Timing is Everything

    Depending on the engine and type of piston design, the points contact must occur before the point when the piston is just beginning the return part of its cycle. This allows the piston to absorb the impact of the spark and combustion and translate that energy into pushing the connected engine parts. As an engine's speed increases, the timing of the spark must occur earlier and earlier to compensate for the faster cycle. If the ignition points are misaligned or do not engage with the correct timing, the spark from the spark plug won't fire at the right moment.

Bad Timing, Bad Spark

    Some might think as long as there's combustion the engine should run, so perfection in points timing is not necessary. This is a fallacy. If the timing of the points' spark occurs too fast, pre-ignition occurs. This condition may create a hot spot on the piston head, causing it to melt a hole in the piston surface. After that, compression is lost and the engine fails. Post-ignition or late spark misses the compression of the piston, causing the engine to bog or run poorly. Eventually the spark plug tip fouls from too much fuel and not enough combustion.

Setting the Points for Correct Spark

    Point-condenser systems require a manual setting. The mechanic removes the flywheel and determines where top dead center is in the engine's piston cycle. He then backs up the crankshaft until it reaches the appropriate degree prior to top dead center. This positioning is determined by the mechanic with a degree dial disc or a timing strobe gun. Once the proper degree is found, then the points are positioned and locked into place to be driven by the rotation of the crankshaft arm. The flywheel is re-installed and the engine is then tested for operation. Proper spark and timing will be evident by a well-running engine with a chocolate brown tip on the spark plug, assuming the carburetor is working properly as well.

Can a Car Fuse Go Bad Without Blowing?

Can a Car Fuse Go Bad Without Blowing?

The sacrificial device known as the fuse is the only protection your radio, lights, and other electrical components have. Technically speaking, a fuse doesnt actually go bad -- a blown fuse has actually performed its job exactly as intended. That's a good thing, but it implies that there was something wrong elsewhere in the circuit. Due to the way fuses are engineered, the likelihood that a fuse would become faulty without blowing is pretty slim, but there are rare instances in which a fuse might appear completely fine, even though no current runs through it.

What a Fuse is Made Of

    The most common types of automotive fuse are the blade fuse the mini fuse (though the mini is really just a smaller version of the blade). The two terminals (or blades) that go into each end of the fuse are only connected to each other in the middle by copper, silver, aluminum, zinc or some other alloy that can predictably maintain continuity for many years. The material inside the fuse must be able to handle its rated current capacity, and the center connecting element must respond to the slightest overdraw of current by melting rapidly.

The Need for Fuses

    The electrical circuits in your vehicle are designed to carry a very particular electrical load the battery to the components. The size of the wire and amperage rating of the fuse is determined by the current draw created by the connected electronics. Changing the components in the circuit can have an unpredictable effect on the amperage and resistance in the circuit, which is why you never jump to a higher fuse and never add extra electronics (like lights or a radio) that were not a part of the vehicle's original design. If there is a fault with one of your components or a short in the circuit, the extra current draw will likely exceed the amperage rating of the wire. This can cause the wire to melt and perhaps even catch fire.

Doing its Job

    Each fuse in your fuse box is designed to fail when the circuit is overloaded. The amount of time it takes for the fuse to blow varies depending on the material used in the center of the fuse and the amount of overload in the circuit. When there is excessive current, heat is generated and the center of the fuse melts and breaks the circuit to prevent further damage down the line. In many cases, you may be able to just replace the blown fuse and move on, because whatever caused the excessive draw was temporary or only created a momentary surge.

How to Tell if a Fuse Is Blown

    Remove the fuse that you suspect to be blown and visually inspect the center element through the case. The melting action often causes discoloration of the case, and the center element should have an obvious break. Another thing to check: Look for a small square opening on the top of the fuse above each blade. Set a multimeter to the continuity setting and probe these openings with your multimeter leads and see if there is continuity through the center portion of the fuse. If there is little-to-no continuity, the fuse is bad and needs to be replaced. This is a good test to double check a fuse that is not a part of the car's circuit, but do not test the fuse while it is in the fuse box. That's because if there is a serious problem with the circuit, the multimeter will complete the circuit, damaging your meter.

How Do I Check Trouble Codes for a '95 Cutlass Supreme?

How Do I Check Trouble Codes for a '95 Cutlass Supreme?

The 1995 Cutlass Supreme predates the current generation of on-board diagnostic codes, so the current OBD-II scan tools on the market, will not be able to comprehend its trouble codes. These scanners are not reverse compatible. You need a diagnostic scanner fluent in OBD-I. These tools are still available as of 2010, and can be found online. The process of checking the trouble codes is basically the same as it is for contemporary vehicles using the current diagnostic coding system.

Instructions

    1

    Connect the scanner's cable to the diagnostic scanner. Turn on the scanner.

    2

    Turn the key in the ignition. This allows data to stream from the diagnostic system to the OBD-I. This should only take a second or two.

    3

    Read the code as it appears on the scanner's screen. Write it down and look up the code online to find a definition. There are plenty of sites that archive these codes.

How to Troubleshoot a Strut Assembly

Struts contribute to the handling performance and comfort of your ride in your vehicle. Like any mechanical component, struts and shocks become worn. This not only poses a threat to your safety, as braking power and handling diminish with bad shocks, but worn struts can make the vehicle ride harsh and uncomfortable. Because strut replacement is an expensive repair, it's best to examine your struts, and determine they need replacement, before performing any work.

Instructions

    1

    Turn off the air conditioner and stereo, and take the vehicle for a short drive in an area that has obstacles that would cause the vehicle to bounce, such as speed bumps, small pot holes or dips in the road.

    2

    Drive over an obstacle, slowly, monitoring any excessive bounce in the front or back wheels. Excessive bounce is indicative of bad struts.

    3

    Listen to the struts as you drive over the obstacles. Grinding, scraping and knocking noises are good indicators that your struts are bad.

    4

    Raise the front or rear of the vehicle with a hydraulic jack (depending on which struts you assume are bad), unless you can clearly see the strut assembly while the vehicle is on the ground. Shine a flashlight in the wheel well, and look for leaking fluid, grease buildup on the strut assembly or broken mounts. These are clear indicators that your struts are shot. The strut assembly is a hydraulic shock absorber with a coil spring wrapped around it and connects from the axle to the vehicle chassis.

    5

    Park the vehicle on an even surface. Measure the distance from the top of the wheel well to the ground for each wheel. Compare the right and left sides (do not compare back and front, as some vehicles purposely sit higher in the front or back), or compare the distances to the specifications in the vehicle service or reference manual.

How to Troubleshoot the Ignition on a 1992 Ford Ranger

Ford's 1992 Ranger pickup truck was sold with a five-position ignition lock. Unlike many recent Ford ignition locks, the Ranger's includes a "Lock" position in addition to the more usual "Accessory," "Off," "On" and "Start" positions. Problems with the ignition on a Ranger can be related to function, key removal and chiming. You can troubleshoot these kinds of problems by following these steps.

Instructions

    1

    Press the key release lever if your truck has a manual transmission gearbox mounted on the floor and you want to change the ignition key from the "On" or "Off" position to the "Accessory" position. The lever is on the upper right of the steering column, above the key lock. Press and hold it.

    2

    Close the driver's door if a chime sounds while the key is in the ignition. Alternatively, remove the key.

    3

    Follow the correct procedure to remove the key depending on the Ranger's configuration. To remove the key if the vehicle has a gearshift lever on the steering column, put the shift in "Park" and set the foot parking brake. Then turn the ignition to "Lock" and remove the key. If the gearshift is on the floor, place the shift into first gear, turn the key to "Off," set the brake and push and hold the key release lever. Then turn the key to "Lock" and remove the key.

Senin, 20 September 2010

My 2004 F-150 Dies When Turning

Your truck's engine does a lot more than just allow it to accelerate; it powers several ancillary systems responsible for helping you to stop, turn the wheel, keep your battery charged and keep yourself cool while doing it. Stalling while turning usually isn't a failure in the motor itself as much as a failure in one of its most powerful hydraulic systems.

Power Steering Basics

    A power steering system like the one used on the F-150 is essentially an hydraulic pump that supplies fluid to a two-way hydraulic ram. When you turn the wheel, the engine-driven pump shoves fluid to a pressure manifold in the steering ram. Depending upon which direction you turn the wheel, one of two valves will open; one routes pressure to the left-side ram -- which pushes the wheels to the right -- and one supplies pressure to the right-side ram.

Pump Function

    A power steering pump is a positive-displacement unit, meaning it will always move the same amount of fluid per revolution regardless of pump rpm. That's a good thing when you're turning the wheel, when pressure from the pump routes through those valves and into the ram. The rest of the time, that fluid just recycles through a spring-loaded bypass valve in the power steering pump, which send it back into the reservoir.

Hydro-Locking the Pump

    If the pump's bypass valve fails to open, or to open all the way, a certain amount of the pump's pressure will back up in the system. This pressure hydro-locks the pump, slowing it down or keeping it from turning. You can hear the sound of fluid trying to rush through the narrow bypass opening -- it often manifests as a loud whoosh or groan. If the pump meets too much resistance via hydro-locking, the power steering belt will resist crankshaft movement, stalling the engine.

Other Causes

    Depending upon the specific engine installed in your truck, your motor may rely on a computer-controlled idle air control valve to meter air into the engine at idle. Normally, the computer would crack the IAC open a bit more to compensate for the expected rpm drop when you turn the wheel, but a clogged IAC passage or malfunctioning servo valve will choke the engine into a stall once rpm drops below a certain point.

How to Troubleshoot a 1999 Chevy Lumina Brake Light

A brake light that is constantly burning out can be a symptom of a faulty socket, a surge in power or moisture in the light assembly. Testing the brake light bulb, socket and wiring will allow you to discern the reason your brake light is not working. Replacing a bulb or socket takes only a matter of minutes. Replacing the brake light wiring can be more time-consuming and labor-intensive.

Instructions

    1

    Ask your assistant to depress the Lumina's brake pedal. Stand behind the car and inspect the brake lights. If you have only one brake light out, the brake light fuse is working. If both lights are out, ask your assistant to release the brake pedal.

    2

    Open the Lumina's hood and remove the plastic cover on the electronic control center in the engine compartment. Pull the "Brake" fuse, using pliers if needed. Inspect the inside of the fuse to make sure the fuse center is not broken. If the fuse is bad, replace it and retest.

    3

    Open the trunk of the Lumina. Peel the trunk liner away from the inboard side of the taillight assembly. Remove the brake light bulb and socket from the fixture by turning it counterclockwise. Check the light bulb for imperfections, such as blistering on one side or a blackened bulb lens. If the bulb lens is damaged or the filaments inside the bulb are broken and no longer connected, replace the bulb.

    4

    Ask your assistant to sit in the driver's seat of the Lumina and depress the brake pedal again, if the bulb seems to be in good condition. If the lights are working properly, the bulb should light up. Wiggle the light bulb in the socket by wrapping the bulb in a paper towel and moving it with your fingertips. If the light flickers on and off while the brake pedal is depressed, the bulb socket needs to be replaced.

    5

    Ask your assistant to let go of the brake pedal if the bulb does not light up at all when you wiggle it. Wrap the bulb in a paper towel and remove it from the socket. Place the bulb in the trunk of the car. Inspect the inside of the socket for burn marks or melted plastic. If either of these are present, replace the socket. Turn on your multimeter and set it to the volts setting. Insert the probes from the multimeter into both of the socket plug holes.

    6

    Ask your assistant to depress the brake pedal. If you get no reading from the bulb socket, the wiring to the socket is shorted out and needs to be replaced.

The Causes of 4-Wheel ABS Brake Failure

The Causes of 4-Wheel ABS Brake Failure

As the old adage goes, an ounce of prevention is worth a pound of cure. To prevent ABS brake failure, replace your brake fluid every two to four years and use the type recommended by the manufacturer. Have your calipers, pads and the rest of the brake system checked annually, even if there are no obvious signs of a problem--some issues start small or are difficult to hear if you like to drive while talking or listening to music.

Sensor Problems

    Failure of ABS systems is almost unheard of except in older systems; far more commonly, dirt gets into the sensors and activates the ABS light on the dash. Your mechanic can isolate and clean the sensor registering the issue to see if this is the problem.

Faulty ABS Systems

    The Bendix ABS-10 system on pre-1993 Chrysler and some GM vehicles was manufactured with a bad pump. Affected vehicles include the 1990 through 1993 models of the Imperial, Cherokee, Dynasty and New Yorker, as well as some models of the Caravan, Voyager and Monaco. Because of this problem, the manufacturers have placed a lifetime warranty on this part.

Fuse Problems

    Some early 1990's model vehicles have ABS-controlling fuses that are especially sensitive to changes in voltage, and the fuse may blow if you need to jump start your vehicle. If your ABS warning light turns on after a jump start, try replacing this fuse.

Grease or Oil

    Brakes, at the simplest level, work by using friction to halt the vehicle. If grease or oil makes its way onto your brakes, ABS or not, they will not work properly. If your brakes are sliding or failing, check them for oil that may have been deposited there by a leak from a failed seal.

Vibration When Applying the Brakes & Turning Right on a 2005 Chevy Colorado

The Chevy Colorado, has, since its introduction in 2004, proven itself a fairly reliable pickup and successor to the wildly popular S-10. But, like all machines, the Colorado's mechanical bits won't last forever -- especially if you use the truck the way that you're supposed to use a truck. While the Colorado isn't necessarily any more prone to this kind of failure than any other vehicle, to paraphrase Forrest Gump: "Stuff happens."

Vibration Under Braking -- Warped Rotors

    Vibration under braking is generally the result of warped brake rotors. As the high spots on the rotor pass the pads, they push back on the brake cylinders and shove upward on the brake pedal. When you overheat a rotor, the hottest portions of the rotor's metal will reform and re-crystalize into a very hard, very rough form kind of ceramic known as cementite. As the pad clamps down on the rotor afterward, it wears away at the softer, original pad material and creates depressions. Thus, often times, you wind up with a "warped" rotor that isn't really warped; it's just uneven.

Vibration Under Braking -- Steering Components

    Most kinds of damage to loose or worn steering system components will cause vibration and steering wheel shimmy while turning. You'll want to inspect your tie rod end links and steering components all the way through the steering box and up the steering column to the firewall. If you find nothing wrong, that doesn't mean that there isn't a problem; hydraulic valve malfunctions in the steering box and power steering pump can cause vibrations while turning. However, they should be unaffected by braking.

Vibration While Turning and Braking -- Tires and Wheel Bearings

    Tires contain polyester, composite or fiberglass belts that keep the tread stable under conditions like turning and braking. Under cruise conditions, centrifugal force will spin the tire outward and keep it relatively round. But turning while braking transfers a significant portion of the truck's weight to the front-outside tire; in this case, the left-front tire. If you suspect a broken or damaged belt, try swapping the front tires. If the vibration now occurs when you turn left, you've found the problem. Bad wheel bearings will exhibit many of the same symptoms, but are generally accompanied by grumbling, growling or screeching noises.

Vibration While Braking and Turning -- Limited Slip Chatter

    Four-wheel-drive Colorados and Canyons have always been offered with an optional Eaton limited slip differential. An LSD, like the one the Colorado uses, utilizes a series of internal clutch discs to lock the left and right axles together when one starts turning faster than the other. But the LSD has a limited capacity to split torque and is designed primarily to handle only the engine output. And brakes, as a rule, are many times more powerful than engines. Clutch-type LSDs will often chatter -- rapidly engage and release -- when the friction material starts to go bad, or the fluid's worn out. If your clutches are worn out, the mechanism malfunctions or you use an oil without the proper friction modifier, then turning while hitting the brake is almost certain to induce clutch chatter.

How to Isolate a Bad Ignition Coil on a 2006 F-150 With a 5.4L V8

The Ford F-150 remained a relatively simple machine that didnt even see the benefit of fuel injection until 1987; but starting in the late 1990s, Ford went on an electronic control craze. One system in particular has given F-150 owners headaches since its release: the coil-on-plug ignition system. Ford designed this system to give the pickup more power, while lowering emissions and fuel consumption. It also added a new problem: the notorious Cylinder X Misfire code. This system has eight coil packs in total, so isolating the failed ignition coil on the 5.4-liter engine may be a little tricky.

Instructions

Identifying the Cylinder

    1

    Plug the OBD-II scanner into the data link connector on the lower drivers side of the dashboard. Turn the trucks ignition to the Run position, but dont start the ignition. Begin the scanners scan function and observe as it connects to the trucks computer system.

    2

    Read the codes displayed on the OBD-II scanner. The scanner will describe one code as Misfire Cylinder No. X, with the X representing the cylinder number that has a firing problem, if it is a single misfire. A Multiple Cylinder Misfire code means there is a problem other than a single coil pack.

    3

    Compare the cylinder number listed on the scanner with the layout of the F-150s engine. Ford numbered the cylinders 1-2-3-4-8-7-6-5, starting from the front passengers side of the engine and moving clockwise around the engine. This identifies which coil requires testing.

Testing the Failed Coil

    4

    Verify the coil pack wiring harness is plugged in. If the harness is not plugged in, say duh, slap your forehead with your palm, plug it in and recheck the operation of the F-150. If the harness is plugged in or continues to have a misfire after plugging it in, proceed with the testing process.

    5

    Pry upward on the passenger's side door scuff panel with a flat-head screwdriver to disengage its retaining clips, then remove the panel. Open the fuse panel door on the passengers side kick panel by opening it until its perpendicular to the kick panel, then pulling its curved tabs from the kick panel. Pry outward on the center pin on the pin-type clip on the top corner of the kick panel with a flat-head screwdriver, then pry the clip from the kick panel. Remove the kick panel.

    6

    Remove the two screws securing the inertia switch using a ratchet and socket, and pull the inertia switch away from its mount until you can access its wiring harness. Pry upward on the locking tab on the inertia switchs wiring harness, then unplug the harness.

    7

    Start the engine and allow it to stall. This eliminates all fuel from the lines, not allowing the truck to start during the testing process.

    8

    Unplug the wiring harness from the inoperative coil pack and look at it with the locking tab facing down; the pin on your left is the Ign Start/Run pin and the one on your right is the COP pin. Look at the powertrain control module located under the hood and notice there are three wiring harnesses plugged into it. The harness on the drivers side of the truck is the engine harness. The engine has four rows of wires. The wires harness closest to the top consists of pins 1 through 17, from right to left. The second row down houses pins 18 through 33, from right to left. The third row down contains, from right to left, pins 34 through 50. The final row of wires on the harness houses pins 51 through 66, from right to left.

    9

    Determine the pin on the PCM that matches up with the coil pack you are working on. Cylinder 1 uses pin 17; cylinder 2 uses pin 11; cylinder 3 uses pin 12; cylinder 4 uses pin 14; cylinder 5 uses pin 10; cylinder 6 uses pin 15; cylinder 7 uses pin 16; and cylinder 8 uses pin 9

    10

    Touch one end of a non-powered test lamp to the Ign Start/Run pin in the coil packs wiring harness; contact the other end of the test lamp to the corresponding pin on the PCM for that coil pack, as determined in the previous step. You can stab the PCM wire with the sharp end of the test lamp or use a thin probe attachment on the end of the test lamp to make contact with the PCM pin inside the harness.

    11

    Crank the engine and watch for the test lamp to pulse continuously. If the test light consistently blinks, there is a pulse coming from the PCM to the coil pack, and you may proceed to the next step. If there is no blinking, or there is inconsistent blinking, the problem is in the wiring or powertrain control module, not the coil pack.

    12

    Turn the ignition to the Off position. Remove the bolt securing the coil using a ratchet and socket. Pull the coil off the engine with a slight twisting motion. Press one end of a spark tester inside the coil, like a spark plug would go. Press the other end of the tester onto the spark plug. Adjust the spark tester to a gap of between 0.040 and 0.050 inches. Instruct an assistant to crank the engine as you watch the spark in the tester. If the spark is a bluish white, the problem is in another system, such as fuel or air intake. If the spark is a red or orange color, the coil failed.

Minggu, 19 September 2010

How to Shut off the Check Engine Soon Light on a 2000 Ford F-150

Prior to the 1996 conversion to on-board diagnostics-II for all vehicles, diagnosing an electronic failure on a car was tough. Each manufacturer had its own diagnostic protocol, resulting in mechanics potentially not having the tools required to diagnose your vehicle. With the government-mandated switch to OBD-II, all manufacturers had to fit their vehicles with the same system. This resulted in a significant reduction of gizmos in a technicians toolbox, as he only needed one scanner to diagnose all post-1996 vehicles, including the 2000 F-150. Shutting off your F-150s Check Engine light requires a diagnostic scanner, which you can rent from a nearby auto parts store.

Instructions

    1

    Adjust the drivers seat as far back as it will go and look under the drivers side of the dashboard to find the data link connector the male receptacle in the same shape as the plug on the end of the OBD-II diagnostic scanner.

    2

    Plug the OBD-II diagnostic scanners plug into the F-150s DLC.

    3

    Turn the F-150s ignition to the run position, but do not start the pickup. Most scanners boot up automatically at this point, but some do require you to turn them on manually.

    4

    Enable the OBD-II diagnostic scanners code scanning feature. This process varies between scanners, but most diagnostic scanners have a Scan button on them. Refer to the scanners instructions for specifics.

    5

    Observe as the scanner communicates with the F-150s computer and displays the diagnostic codes on its screen.

    6

    Activate scanners code deletion feature. This process differs between scanner models, but most you simply toggle down to Erase Codes or Delete Codes and press enter, then follow the prompts on the screen. Refer to the scanners instructions for specifics.

    7

    Watch as the scanner goes through its code deletion process, then prompts you when it finishes erasing the codes.

    8

    Turn the F-150s ignition to the Off position and unplug the scanner from the DLC.

The Check Engine Light Came on & Radiator Fan Is Now Continuously on for My 2004 Audi A4

The 2004 Audi A4 was available with an optional 1.8-liter turbocharged in-line four-cylinder engine, or a 3.0-liter V-6. The cooling fan on the 2004 A4 is responsible for forcing cold air through the fins of the radiator, lowering the temperature of the engine coolant. If the cooling fan is constantly on and the "Check Engine" light is on, the vehicle should be scanned to help locate the problem. The coolant temperature sensor sends signals the engine computer on the A4 to instruct the cooling fans to turn on and off.

Instructions

    1

    Kneel next to the driver's side of the A4. Locate the OBD-II plug port beneath the dashboard. Insert the OBD-II scanner plug into the port. Turn the ignition key to the "II" accessories position. Press the power button on the scanner to boot the scanner.

    2

    Follow the prompts on the scanner to select your vehicle, using the "Up" and "Down" arrow buttons. Press the "Read" button to accept your answers. Select the option for "Trouble Codes" and press the "Read" button. Allow the scanner to communicate with the A4.

    3

    Collect the data from the scanner to help diagnose what the problem is with the Audi. Perform the repairs necessary to eliminate the source of the trouble codes.

    4

    Scan the A4 after you have made the repairs, using Steps 1 through 3. If you have performed the proper repairs, the trouble code will be gone. If the trouble code still exists, you have not made the proper repairs.

Problems Caused by Exhaust Manifold Leaks

No, your car isn't shooting at you, but that irritating little tap may still precede the same state as any bullet. Exhaust leaks won't necessarily destroy your engine; while fires are possible, the realistic worst-case scenario is that they'll cost you a bit of money in machine work. But that might not matter to you, especially if you end up falling asleep before you get to the machine shop.

The Big Sleep

    Make no mistake: exhaust manifold, header leaks and the associated gasses are deadly. Engine exhaust contains large amounts of carbon monoxide, a molecule that bonds to the hemoglobin in your bloodstream. Hemoglobin is like a sponge, picking up oxygen molecules and ferrying them to the cells in your body. Carbon monoxide "clogs" the hemoglobin's pores, leaving no room for oxygen. Carbon monoxide-filled engine compartments will eventually leak some of this odorless, colorless gas into your car, leaving you extremely sleepy and dead. Fun fact: Carbon monoxide-saturated blood looks remarkably like orange Kool Aid.

Flange Corrosion

    Exhaust manifold leaks tend to start small, but they have a way of getting bigger and bigger. Hot gasses shooting through the leak do two things: They degrade the gasket surface and they corrode the manifold and manifold mating surface on the head. This heat-induced corrosion carves a tiny channel out of the mating surface, one that may or may not require machine work to fix. Granted, this kind of damage does take a while to have an effect, but it will happen eventually.

Engine Malfunctions

    Most modern automobiles draw their air in from the outside or through the fender-well and well away from the engine. Cold-air induction came into common practice in the 1970s; prior to that, most automobiles drew air in from the engine compartment. Carbon monoxide doesn't burn and it displaces oxygen, which will have the same basic effect on the engine that it will on your body. Sooner or later your car's motor is going to suffocate, loosing power and possibly stalling until the carbon monoxide clears out. Of course, if you've got an exhaust leak big enough to choke an engine out, odds are that you're too dead to drive.

Detection

    Exhaust manifold leaks can be difficult to track down, especially on front wheel drive cars where one manifold is positioned in the back. The simplest way to find a manifold leak is to squirt the manifolds with soapy water and watch for bubbles. Your car's manifolds will need to be stone-cold for this check, since a hot manifold will quickly boil the soap-water mixture and cause it to bubble everywhere. Alternatively, you could hold a six-inch-long strip of paper of the manifold mating surface and watch for it to puff out a bit. The third option (if you don't have a mechanical cooling fan) is to drive to your local oncology center and find someone who smokes. Have your assistant blow a thick cloud of smoke around the manifold and watch for air movement. This approach works particularly well for finding leaks hidden under the manifold and in out-of-the-way places.

Myths, Busted

    Some old-timers will tell you that an exhaust manifold leak will fry your engine or burn the exhaust valves. There is some logic behind this, since exhaust streams do temporarily reverse when exiting the tube; that's why we use manifolds in the first place. However, the tiny amount of air sucking back in through that leak is unlikely to make it into the combustion chamber. And even if it does, only a major leak will supply enough oxygen to cause a radical change in the air-fuel ratio, since the air around the leak is more than likely saturated with carbon monoxide.

Blazer 4.3 Ignition Coil Test Procedures

Introduced in 1983, Chevrolet's Blazer was a three-quarter-sized SUV for people who needed an SUV without the full-size hassles. So, GM's own "three-quarter small-block" seemed like a natural fit for the chassis. Essentially a 350 V-8 with two cylinders hacked off, the resulting 4.3-liter was powerful, compact, and had an exhaust note unlike anything this side of a V-8. Coil-testing procedures for the most prevalent Vortec 4300 version are understandably identical to those used for the engine's V-8 siblings -- and just as easy.

Coil Basics

    The Vortec series of engines were something of a high point for the old small block; think of a caveman armed with a jetpack and a laser cannon, and you've got the idea. The final iteration of this classic design still used a distributor and even used a separate "divorced" coil mounted to the manifold. But that coil was actually a two-part unit. Half of it was the actual coil; the other half was the ignition control module. So, when you look at the coil, you'll see two wiring harnesses -- a three-wire harness in the top going to the coil and a four-wire harness in the front going to the module.

Identifying the Terminals

    Depending on the truck, your terminals may already be lettered on the connector. But if not, on the three-wire connector: the A-terminal (pink wire) corresponds to the 12-volt power circuit, the B-wire (white) goes to the tachometer and the C-wire (black and white) provides the switching signal from the ignition module. On the four-wire plug, from top to bottom: The A-wire (pink) is the 12-volt power wire, B-wire (white) is the ignition control signal, C-wire (black with white stripe) is the engine ground and D-wire (white with black stripe) is the switching signal circuit. Realistically, the three-wire terminal doesn't matter for these testing purposes -- but it's nice to know what all this stuff does.

Testing the Power Supply

    Start by setting your digital multimeter to read voltage in DC mode and fit a sharp needle-probe to it. With the ignition key in the "on" position, place the black probe lead on the battery's negative terminal, then poke the red lead into the A-wire (pink) -- you should see between 10 to 12 volts. Now, touch the red DMM lead to the battery's positive terminal, and poke the black lead into the C-wire (black with white stripe); again, you should see between 10 to 12 volts. If you didn't get these results, then your problem is the power supply, not the coil/module.

Testing the Switching Signal

    For this test, you'll need an LED-style test light; an incandescent test light won't turn on and off fast enough to give you a result. Start by unplugging the four-wire harness from the module. Connect the red lead on your LED test light to the battery's positive terminal and connect the black lead to the D-wire (white with black stripe) on your harness. Have an assistant try to crank the engine -- you should see the light flicker on and off very quickly. If it flashed on and off while your engine was cranking, then the ignition coil is almost certainly bad. If not, then you've got a problem with the ignition control module or somewhere else.

Testing the ICM

    Plug your connector back in. Pierce the white B-wire with the needle probe on your LED test light's negative wire. If you don't have a needle probe, then poke an actual needle into the wire and clamp the negative wire to the needle. Touch the LED light's positive lead to the battery's positive terminal, then crank the engine again. If the light flashed on and off while you cranked the engine, then the ignition control module is bad. If it didn't, then you've likely got a problem with the computer, the crankshaft position sensor, or a severed wire or loose connector somewhere between the ignition module and the computer.

Sabtu, 18 September 2010

What Is a Normal Reading for the Oil Gauge?

What Is a Normal Reading for the Oil Gauge?

The normal oil pressure in an internal combustion engine varies from one brand to another and one model to another. What's normal for a Chevrolet engine may be different for a Toyota engine and the normal pressure for a 4.3L Chevrolet may be different than on a 5.7L Chevrolet motor. Still, oil pressure is an important monitor of how well the engine oil is protecting the moving parts of an engine.

Mid-Range is Best

    Oil pressure will vary in most engines depending on whether the engine has just been started and the oil is cool or if the motor has run long enough to warm to normal operating temperature. The pressure will vary somewhat with the speed the engine is turning. That's why many vehicles only have gauges that show low, normal and high ranges. Check the specifications for the exact make and model engine for your vehicle to determine the correct oil pressure operating range in pounds per square inch. Gauges that register in PSI, usually range from 0 to 100 and the normal zone on these is between 20 and 80 PSI.

Considerations

    The oil pressure gauge measures the resistance to the oil being pumped through the engine by the motor's oil pump. The temperature of the oil, the type of oil and it's viscosity all affect that resistance. The age of the engine affects oil pressure, as well. New, tight engines will register higher oil pressures than the same engine thousands of miles later after it has been broken-in and has experienced some internal wear.

Low Verses High

    Low oil pressure indicates insufficient lubrication is being provided to the motor. A reading less than 20 PSI or under the normal range on the gauge is cause for immediate attention. The problem could be as simple as a low oil level or a signal of serious engine problems. High oil pressure readings are uncommon and may be a faulty gauge or an improperly functioning oil by-pass valve.

How to Test If a RAV4 Brake Booster Is Working

The Rav4 is a small and sporty SUV made by Toyota. Since its introduction in 1996, the Rav4 design has undergone a number of significant overhauls; however, all Rav4 models are equipped with power brakes that make use of a vacuum booster. As with all such power brakes, any problems with the brake booster can seriously impede their operation, and Rav4 owners should test the brake booster from time to time to ensure it is in proper working order.

Instructions

    1

    Park your Rav4 and, with the engine running, depress and hold the brake pedal with light but steady pressure. Turn the engine off, continuing to hold the pedal down for about 30 seconds. The brake pedal should stay in the same position, signifying that the booster is not losing vacuum. If the brake pedal slowly rises during this time, this means that the booster is not air-tight.

    2

    Turn the engine off and pump the brake pedal a few times to use up any vacuum remaining in the booster. Depress and hold the brake pedal, and start the engine. As soon as the engine starts, the brake pedal should drop slightly, signifying that the brake booster is functioning properly.

    3

    Let the engine idle for a minute or two. Turn the engine off and immediately pump the brake pedal six or seven times, waiting two or three seconds between each pump. If the brake booster is air-tight, then the brake pedal will stop at a slightly higher position with each pump. If there is a leak in the booster, the pedal will stop at a high position on the first or second pump, and will return to this same high position on the following pumps.

2003 Toyota Camry Xle Suspension Issues

The Toyota Camry was introduced in 1983; it is considered one of the most dependable and popular mid-sized sedans on the market according to Edmunds.com. The 2003 Camry XLE is equipped with a 3.0-liter engine and solid safety and luxury features.

Pulling

    About Automobile, a database of driver complaints, TSBs and recalls, states that the most commonly reported Camry XLE suspension issue is the vehicle "pulling" to the left. Camry XLE owners reported that the vehicle drifts to the left without warning. Camry XLE drivers stated that the pulling affect is more profound when driving at highway speeds.

Vibration

    Auto Recalls For Consumers states that Camry XLE drivers reported front-end vibration. The majority of drivers felt front-end vibrations while driving at various speeds, but reports were filed of "violent" vibrations at speeds above 40-mph.

Solution

    The Camry XLE's "pulling" problem is typically due to improper wheel alignment, which might be the result of driving over holes or bumps in the road. The front-end vibration problem is likely the result of failing ball joints. This failure permits the vehicle's wheels to swivel when the steering wheel is turned.

Rabu, 15 September 2010

2001 Toyota Rotors Repair

2001 Toyota Rotors Repair

In late 2002, Toyota began to address brake rotor problems in many of its larger 2001 vehicles -- including the Tundra, the Highlander, the Sequoia and Toyota minivans -- since a caliper design was causing premature warping of rotors.

The Problem

    Due to an inaccurate design of the caliper, brake pads would place pressure incorrectly on the brake rotor surface. A new vehicle would begin to suffer serious vibrations as the driver applied the brakes at high speed. The shaking came from rotors becoming warped and the fluctuations shaking through the assembly to the vehicle.

First Reputation Damage

    Until the 2001 vehicle rotor problem occurred, Toyota generally maintained a strong reputation for quality vehicles. However, the rotor problem represented a smear on that record. The voluntary recall came late, only adding to the reputation damage as dealers hesitated to perform the needed work.

The Repair

    Toyota began a voluntary recall under TSB br004-002 to swap out the 191 millimeter calipers with larger 231 millimeter calipers. Some dealers were hesitant at first, not wanting to absorb any costs in their own operations. However, after a company-wide notice, the caliper replacement became a standard procedure for warrantied cars.

How to Turn Off the Check Engine Light in a 97 Ford Taurus

The check engine light on a 1997 Ford Taurus is a communication device between you and the power train control module. The module monitors all the sensors in the power train. If any sensor returns a fault to the module, it generates a diagnostic trouble code. The storage of a code automatically triggers the illumination of the check engine light to alert you to the fault. If you understand the basics of automotive repair, you can turn off the 1997 Taurus' check engine light in a matter of minutes.

Instructions

    1

    Plug the scan tool's datalink cable into the Taurus' diagnostic port located under the dashboard next to the steering column. The diagnostic port is the same shape as the end of the datalink cable and covered with a black plastic dust cap that you'll need to remove by hand first.

    2

    Switch the Taurus' ignition to the run position. Proceed with a quick test on the scan tool, following the scan tool's specific user guide for performing the test. This procedure varies from brand to brand and model to model.

    3

    Erase the diagnostic code(s) when the scan tool display queries if you would like to do so. Complete the quick test per the scan tool's user guide.

    4

    Turn the Taurus' ignition off and remove the key. Unplug the datalink cable from the diagnostic port and place the dust cap back on the port.

Selasa, 14 September 2010

What to Do If AOD Will Not Shift Into Overdrive

What to Do If AOD Will Not Shift Into Overdrive

    Vehicle transmission problems can be simple or complex.
    Vehicle transmission problems can be simple or complex.

Mechanics Are Experts

    Transmissions with automatic overdrive are complicated mechanisms. Seldom does one part fail without affecting other parts. Repairs are expensive, but replacing the transmission or a complete rebuild will cost even more. Take it to a transmission service shop with trained experts.

It Might Be a Simple Problem

    Don't be like a homeowner who calls the electrician for a burned out light bulb. Check the transmission fluid. Most vehicles have a switch or button to disable the automatic overdrive (AOD) feature when towing or hauling heavy loads. Make sure the AOD is enabled. Older vehicles have a mechanical linkage between the shift lever and transmission. These can wear and loosen with age. Try jiggling the lever or moving it up or down one position.

Bottom Line

    Don't ignore the situation. Do a few simple checks to make sure the problem isn't something minor. If everything you can do checks out, get the vehicle to a repair shop as soon as possible.

How to Troubleshoot a Jeep Wrangler Manual Transmission

How to Troubleshoot a Jeep Wrangler Manual Transmission

The Jeep Wrangler is a compact and powerful automotive legend. While it is renowned for its toughness and versatility, it can encounter problems just like any other vehicle. If your Jeep Wrangler is refusing to start or behaving erratically when you try to shift gears, you can troubleshoot its transmission on your own. You will not need any tools for this procedure, and it requires no special training. You should be able to complete troubleshooting the transmission of your Jeep Wrangler within an hour.

Instructions

    1

    Check the level of transmission fluid in your Wrangler if you find it difficult or impossible to shift gears. A low level of transmission fluid can cause your transmission to overheat and burn up. The dipstick is located on the side of the transmission, beneath the vehicle. Fill the transmission to the proper level with gear oil.

    2

    Ask a mechanic to inspect your Wrangler's clutch if your transmission seems to be behaving erratically, you smell something burning or the engine's rpm is moving inconsistently while you drive. After 50- to 60,000 miles, or after getting too hot repeatedly, the surface of your clutch discs may be glazed, requiring replacement.

    3

    Check your Wrangler's shifting linkage if your transmission has the proper level of fluid but is giving you problems when you try to shift gears. A misaligned or damaged shift linkage may be preventing your vehicle from shifting properly. You can find the shift linkage near the top of your Wrangler's transmission on the driver's side. Watch the linkage closely while a friend shifts the gears of your Wrangler to make sure it is functioning properly. It may only need a small adjustment.

What Could Cause the RPM Gauge to Move While Driving?

What Could Cause the RPM Gauge to Move While Driving?

A tachometer shows how fast an engine is turning over, in revolutions per minute. How that relates to miles per hour on the speedometer depends on which gear is translating the engine's revolutions to those of the wheels. RPM information is most useful with a manual transmission.

RPM Getting Higher

    The car is heading toward a higher gear -- for instance, accelerating to cruising speed. When the gear shifts, RPM will fall again.

RPM Getting Lower

    A drop in RPM can indicate that the car needs to shift down -- for instance, to climb a steep hill. After rapid acceleration, it can also indicate that the car has settled into its cruising ratio, where the engine doesn't have to turn so furiously to maintain steady vehicle speed.

Changes in Gauge Behavior

    If you notice your tachometer shows a different reading in a particular situation, or wobbles up and down without reason, it could be a symptom of a problem you should explore with your mechanic. Don't assume it's something wrong with the gauge itself; speak knowledgeably about your concern for a problem in the engine's communication with the wheels, and be prepared for a transmission or timing-belt repair.

How to Open a Locked Range Rover

How to Open a Locked Range Rover

Range Rovers are popular cars, especially for off-road driving. They are also used as family cars due to their durability and size. Older Range Rover models require manual locking, meaning the car key must be inserted to lock and unlock the vehicle. Newer models have remote locking, in addition to manual locking, so the car can be locked and unlocked by pressing a button on the car key. You have a few options to unlock your Range Rover, even if you do not have the car key. However, it is illegal to break into a car that you do not own.

Instructions

    1

    Check if you have a car key to unlock your Range Rover. If you have lost your key, search for it thoroughly as this is the easiest way to unlock your vehicle. Even if your key is locked inside the car, check if you have a second key. If you find your car key, insert it into the key fob on your car and turn it to unlock the doors. Press the button on your key if your car uses remote locking. Symbols on the car key denote which button to press to unlock your car. If you cannot find your key, move on to the next step.

    2

    Consult your owner's manual. Your manual will contain a telephone number for Range Rover customer service. Call the number and explain that you have lost your car key and your car is locked. Ask for a replacement key for your specific model of Range Rover. You may have to purchase a new key but in some cases you may be offered a replacement key at no extra cost. If you do not have a manual for your car, look for other documents that may contain a telephone number for Range Rover. Check the Internet too if possible. Try the next step if this option does not work.

    3

    Telephone a locksmith if you do not have a number to call Range Rover. You will have to pay for the locksmith to unlock your car and you will not be able to buy a replacement key. If you know your car key is locked inside your vehicle, calling a locksmith is your best option. If you cannot find help, try the final step.

    4

    Walk to an emergency phone box. Pick up the phone and ask for assistance. You should be able contact Range Rover or a locksmith. Your last resort is to call emergency services, but only if you have exhausted all other options.

Senin, 13 September 2010

What Wires When Hot Could Shut Down an Engine?

What Wires When Hot Could Shut Down an Engine?

Vehicle electronics is a complicated subject, and the average automotive electrical system offers dozens of avenues for failures. Difficult to diagnose and hard to track down, hot wiring can mimic all sorts of completely unrelated problems and failures. But no matter which wire's giving you fits, find out what caused the wire to get hot before you go throwing parts at it.

Basic Diagnosis

    Heat and electricity do not get along, particularly when it comes to wiring. An electrical conductor is only capable of moving so much energy on an atomic level. Increase the heat and you increase resistance in the wire and reduce the amount of electricity that can flow through; increase the amount of electricity past the resistance point, and it turns into heat. A hot wire is a cascade effect of failure waiting to happen, since increasing heat increases resistance, which increases heat. Before attempting to fix a hot wire or associated component, find the source of the resistance or short that caused the heat in the first place.

Ignition System

    Hot spark plug wires will typically cause a misfire and loss of power, but they're unlikely to shut an engine down completely. Multiple coil packs won't shut the car down on their own, but any one of the triggering wires might should it meet enough thermal resistance. An extremely hot ignition coil power wire may shut the engine down if you've got a single coil, but odds are you'll experience an intermittent misfire before total shutdown. Because heat increases induce a voltage drop, anything in the ignition system that relies on a precise voltage signal may fail because of heat in the signal wire. The signal wires going to your ignition module require just such a precise voltage and may prove more sensitive to heat than others.

The Ground Wire

    The ground wire is the bridge over which all of the electricity in you engine must cross. Ground wires usually aren't wires at all; they're actually more like flattened ropes of braided steel, like a ribbon running from the engine to the chassis. Over time, the tiny strands in the ground wire will snap -- through corrosion or constant movement -- and the wire will lose some of its ability to transfer energy efficiently. Once enough wires snap, you'll get that cascade effect of failure that causes resistance to build until the wire gets hot and completely stops transferring power. Since every system in your engine works through the ground wire, any failure here will induce multiple failures in the engine electronics and sensors.

Sensor Wires

    While your engines sensor wires are some of the most sensitive in terms of voltage variances, most won't kill your engine outright. The crankshaft position, mass airflow, oxygen, throttle position and manifold air pressure sensors may be important, but the computer has a number of backup "open-loop" sub-routines to keep the engine running in case one of the sensors fails or returns an unlikely signal. Oddly enough, your engine temperature sensor may be the first to suffer from hot-wire syndrome. The temperature sensor works by testing the voltage drop in a conductor set between two electrodes. The hotter the engine gets, the more resistance there is and the more the signal drops. If the sensor wire itself gets hot, it'll send the computer a false reading indicating the engine is overheating. If your computer contains programming to shut the engine down in case of massive overheating, it could easily misinterpret the signal and initiate a self-protection shutdown.