Sabtu, 31 Oktober 2009

How do I Troubleshoot a 1997 Chevrolet 1500 Pickup Fuel Pump?

How do I Troubleshoot a 1997 Chevrolet 1500 Pickup Fuel Pump?

Almost all vehicles on the road today, including the 1997 Chevrolet 1500 pickup truck, come with a fuel pump. The fuel pump sits inside the gas tank and helps ensure a steady flow of fuel from the tank to the engine. The fuel pump needs to be replaced every so often to ensure that the engine receives the fuel it needs as the truck drives. Because the fuel pump sits in a difficult-to-reach place, it is important to troubleshoot whether it needs to be replaced or whether another part of the fuel system has malfunctioned.

Instructions

    1

    Check the truck's fuel pressure. Attach a fuel pressure gauge to the Schrader valve of the engine. The valve is at the top of the engine block and looks like the air valve on a automobile tire. Screw the gauge to the valve, turn on the truck and let the engine idle while you read the pressure level on the gauge. The 1997 Chevrolet 1500 pickup should have between 60 and 66 pounds per square inch of fuel pressure.

    2

    Determine whether the fuel pressure regulator is working right. Even if the fuel pressure gauge reads that the pressure is low on the truck, the regulator may be the cause instead of a faulty fuel pump. Leave the fuel pressure gauge attached to the truck's Schrader valve, turn the truck on and let it idle. Find the black fuel line running to the fuel pressure regulator at the top of the engine. Gently pinch the fuel line next to the regulator with pliers. If the pressure increases as you pinch the line the regulator is faulty, not the fuel pump.

    3

    Listen to the fuel pump before the truck's engine starts. Put the truck's key into the ignition and turn it one notch to the right. The fuel pump should begin working at this point. Because the engine is not yet on you should be able to hear the pump on behind you in the gas tank. Be sure to perform this test in a quiet environment or have a second person help you listen for the pump while you turn the truck's key in the ignition.

    4

    Learn and watch for the truck to exhibit signs that the fuel pump has failed. The two major signs to watch for are the engine stalling when the accelerator is pressed and the engine refusing to start at all.

How Do I Read Trouble Codes on a 1993 Ford Ranger?

How Do I Read Trouble Codes on a 1993 Ford Ranger?

All vehicles manufactured from 1994 onward must be equipped with a code reader plug. This plug is connected to an automotive code reader which informs the user of any problems with the vehicle. On older vehicles, such as the 1993 Ford Ranger, this procedure must be done manually. The user must locate the self test plugs and set the vehicle in test mode. The user then reads the codes displayed by the flashes from the check engine light.

Instructions

    1

    Locate the two plugs required to perform the test on your Ranger. These are in the Ranger's engine compartment on the driver's side fender behind the air filter box. One is labeled the self test plug (STP) and is triangular-shaped with six pins. The other plug is labeled the self test input (STI). This plug is a small, single-pin plug. These plugs may also be labeled "EEC TEST."

    2

    Connect a wire from the negative battery terminal to the STI. Ground the STI by hooking it to another piece of metal. Ground the battery as well by hooking another wire to the bumper.

    3

    Turn the key in the ignition to the "Run" position. You will hear the fuel pump. When the fuel pump stops priming the system, you need to start counting.

    4

    Look at the Ranger's check engine light. It will blink multiple times and then stop. The light will flicker to give a warning that the test is beginning. A code will blink and then pause for two seconds, indicating that it is moving on to the next number in the code. After the code is finished, it will pause for four seconds. If you miss a number, turn the key to the "Off" position, wait 15 seconds then turn it back to "Run." This will restart the sequence. You may need to go through the test several times until you get all the codes.

    5

    Write each of these numbers down.

    6

    Refer to a repair or service manual for your 1993 Ranger or use an online resource, such as FordFuelInjection.com, to determine what the codes mean. Note that there are different lists for two and three number codes.

Jumat, 30 Oktober 2009

Signs and Symptoms of a Sticking Carburetor Float

Signs and Symptoms of a Sticking Carburetor Float

The float in the carburetor regulates the amount of fuel or gasoline which resides in the reservoir. The reservoir of the carburetor is where the fuel is sucked into the intake manifold. A bad or sticking carburetor float causes engine problems. Watch for certain signs and symptoms if you suspect the carburetor float is sticking.

Engine Won't Idle

    One of the signs that the carburetor float is sticking is when the engine will not idle. The float is not letting enough fuel into the reservoir, allowing for a constant idle of the engine. The carburetor float is stuck in the closed position, and only a small amount of fuel is seeping into the reservoir.

Flooded Carburetor

    A flooded carburetor is another symptom that the carburetor float is sticking. The float is stuck in the open position, allowing fuel to run freely into the reservoir and then into the intake manifold. Once too much fuel is allowed into the carburetor reservoir, the carburetor floods and cannot be started until all the fuel is expelled from the reservoir.

Engine Stalls or Hesitates

    The engine will begin to stall or hesitate when the carburetor float sticks. This symptom develops under driving conditions when the operator attempts to accelerate. The engine will act as though is it going to die, but catches and begins to accelerate normally. The hesitation of the engine is a similar event.

Engine Misfiring

    Another sign or symptom of a sticking carburetor float is when the engine misses out or misfires. One or more cylinders are not getting enough fuel or getting too much fuel when they are being fired by the spark plugs. This happens when the float is stuck, either in the open or closed position. The engine will stall, not idle smoothly or backfire once the carburetor float sticks.

Kamis, 29 Oktober 2009

How to Adjust the Clock on a 2002 BMW 325Xi

How to Adjust the Clock on a 2002 BMW 325Xi

The clock on the 2002 BMW 325Xi is located on the dashboard. Now and then -- such as for daylight saving time -- you must adjust the clock by using a small push-button knob that is located on the right side of the dashboard.

Instructions

    1

    Insert the car key into the ignition. Turn it to the "on" position. You do not need to start the car.

    2

    Locate the button on the right side of the dashboard. This is what you will use to change the clock on your BMW. Press it a few times until the clock begins flashing. This means you can now adjust it.

    3

    Push and turn the button to the right to add time to the clock. Turn the button to the left to subtract time from the clock. When the time you want is displayed, release the button. Your clock is now adjusted.

Chrysler Fault Code 340

Chrysler Fault Code 340

There are car diagnostic tools you can purchase for your home garage, allowing you to plug the device into a universal jack in your Chrysler's engine compartment. However, there are a few codes you can find on your own, without expensive equipment.

Find the Code

    If you are not interested in purchasing costly diagnostic tools for your home, there is a simple trick you can use to find the code for free. Turn the ignition of your Chrysler from Off to Run (just before it starts) and back again, in under five seconds. The engine codes should show up in the electronic odometer area of you dashboard. You may have to turn the key multiple times to get this to work properly.

Define the Code

    A Chrysler code 340 is defined as "No camshaft signal being received by the computer."

Fix the Problem

    In the case of a code 340, you will need to take your vehicle to a professional mechanic, as this is not a problem most homeowners can fix. This is just a communication problem between the car's computer and the camshaft. It does not necessarily mean that there's anything mechanically wrong with your car.

Rabu, 28 Oktober 2009

How to Replace a 1998 Pathfinder Bose Radio

The original name for Nissan cars was Datsun, but the story goes back farther than that. In 1914, three Japanese men came together to form an automaker named DAT -- the name was an acronym using the first letter of each man's last name. In 1932, the company changed its name from DAT to Datsun. In 1934, the corporation's name was changed to Nissan Motor Co., thought Datsun still remained as the name of vehicles produced by the company. In 1981, Nissan Motor Co. began a worldwide marketing campaign announcing the changing of its automobile's names to "Nissan." In 1985, Nissan released a new SUV -- the Pathfinder. Replacing the Bose radio in the 1998 Pathfinder is straightforward, once you find the dash bezel screws.

Instructions

    1

    Look on the underside of the dash bezel -- the plastic trim around the radio and air-conditioning controls -- and find the two screws securing it to the dashboard. Remove the two bezel-retaining screws, using a Phillips screwdriver.

    2

    Pull the bottom of the dash bezel upward; listen for the lower retaining clips to unsnap. Work your way up the bezel, pulling it outward to disengage all of its retaining clips. Unplug the wiring harness from the rear of the cigarette lighter by pulling away from the lighter socket.

    3

    Label all of the wires plugging into the rear of the bezel-mounted switches, using a permanent marker and masking tape. Press the locking button on each of the bezel-mounted switches -- hazard lights, fog lights and rear wiper -- and pull each harness from the switch. Remove the dash bezel and set it in a secure location to prevent breakage.

    4

    Remove the four radio-retaining screws, using a Phillips screwdriver. Pull the radio from its chassis in the dashboard until you can access the wires on the rear of the radio. Press and hold the unlock button on each of the white wiring harnesses on the rear of the radio, and pull each harness from the radio. Pull the antenna wire -- the black wire -- from the rear of the radio. Remove the radio from the Pathfinder.

    5

    Plug the two wiring harnesses into the rear of the radio -- they are different shapes, so they can only plug in one receptacle each. Plug the antenna wire into its receptacle on the rear of the Pathfinder's radio.

    6

    Slide the radio into its chassis in the dashboard, lining up the locating pins with the locating holes in the radio's brackets. Tighten the radio-retaining screws with a Phillips screwdriver.

    7

    Plug the wiring harnesses into their respective bezel-mounted switches, and remove the masking tape labels. Plug the wiring back into the rear of the cigarette lighter.

    8

    Line the metal clips on the rear of the dash bezel with the slots in the dashboard. Lightly tap the perimeter of the bezel with your hand to engage the retaining clips. Tighten the two bezel-retaining screws on the underside of the dash bezel.

Selasa, 27 Oktober 2009

Could a Worn Master Cylinder Cause a Brake Light to Come on?

Could a Worn Master Cylinder Cause a Brake Light to Come on?

Master cylinders are the first link in the chain of your hydraulic brake system. The master cylinder is responsible for pushing fluid through the lines, so any failure within it may result in a loss of braking force to the front or rear brake systems. A bad brake master cylinder may or may not trip a brake warning light, depending upon the specific system and type of failure.

Brake System Basics

    When you press the brake pedal in your car, the top of the pedal pushes on a rod connected to a piston inside your brake master cylinder. That piston pushes fluid through the lines and to the brake slave cylinders, which squeeze the pads down on a rotor or the shoes against a drum. The master cylinder piston is actually a two-part unit; pushing the actuation rod pushes the first piston, which pushes on a second via a spring. This creates two chambers that control the front and rear brakes.

Pressure and Brake Sensors

    The average brake system uses a pressure differential switch on the master cylinder to determine whether or not the front and rear brake systems are building the appropriate amount of pressure. If one system builds significantly more pressure than the other, the pressure differential switch trips and triggers a brake warning light. More advanced systems use sensors mounted further along in the individual wheel lines and master cylinder position sensors to determine where the piston is in its travel.

Triggering a Light

    Whether or not a leaking master cylinder triggers a brake warning light depends upon the type of master cylinder, the sensor array and exactly how the master cylinder fails. A master cylinder that fails to build pressure in both circuits may not trip a brake warning light, as there may be no difference in pressure between the front and rear brake circuits. A master cylinder that leaks through one piston more than the other will trigger a brake warning light in most cars, and cars that use a brake position sensor will notice a drop in expected pressure in either or both circuits.

Other Master Cylinder Symptoms

    Whether you actually get a brake warning light or not, there's one sure-fire way to test any master cylinder for internal leakage. Internally leaking master cylinders won't necessarily fail to build pressure; they just won't hold the pressure once its on. With the ignition off, tap your brakes several times until the pedal firms up in order to release pressure from the anti-lock brake accumulator. Once the pedal goes hard, press it as hard as you can and hold it for 15 to 20 seconds. If the pedal slowly sinks to the floor as you hold it in, then odds are that you have an internal leak in your master cylinder.

How to Tell the Difference Between an Exhaust Leak and a Valve Lifter

How to Tell the Difference Between an Exhaust Leak and a Valve Lifter

Engine noise can be hard to identify and even harder to isolate. Sometimes the noise can be frighteningly loud and sound ominous--only to be engine belt noise. Other times the noise can be a tiny ticking that leads to a costly, major repair. Distinguishing between the assorted rattles, squeals, knocks and ticks is somewhat of an art form. Exhaust leaks sputter and are very different than lifter noise or any abnormal engine sounds at all. To accurately diagnose under-hood noise, here are a few guidelines for getting started.

Instructions

    1

    Locate the noise. At times it is difficult to zero-in on the noise, especially since sound will carry through metal. It helps to twist an old newspaper into a cone and listen. The general area of the sound can then be more easily located.

    2

    Isolate the sound. A mechanic's stethoscope will help pin-point the noise; however, it's not foolproof. It's great for distinguishing between a bearing hum or squeal in an alternator or an air conditioning compressor. It will also localize an engine knock to the point that there is no question that the noise is coming from the engine. It cannot, however, be stated with absolute certainty precisely what inside the engine is knocking or where in the engine the knock is located.

    3

    Test for under-hood exhaust leaks. Exhaust leaks are distinct and easily checked. As the vehicle warms up, these leaks get louder. As the metal expands, exhaust manifold cracks and flanges expand, allowing more exhaust gases to escape. They make a sputtering sound as opposed to a lifter with a ticking sound. Exhaust leaks also leave a trail of black soot. It is also easy to smell exhaust fumes under the hood, but they do present the danger of carbon monoxide poisoning.

Minggu, 25 Oktober 2009

Can a Car Battery That Has Died From the Cold Gain Juice in Warmer Weather?

Can a Car Battery That Has Died From the Cold Gain Juice in Warmer Weather?

Car batteries do not mysteriously discharge in cold weather, even in extreme conditions, nor do they mysteriously recharge when they are warmed up. Increasing the ambient temperature, however, can resuscitate reduced performance to a workable level.

Science

    Batteries do not make electricity; they store it. Therefore, a fully-discharged battery does not gain juice from the ether simply because of an increase in ambient temperature. That said, the myth that warming up a cold battery causes it to work better has some grounding in scientific fact. External cold has a distinct effect on a car batterys ability to perform: At 80 degrees Fahrenheit, a battery is at its optimum; at 32 degrees, it can only supply two-thirds of that optimum; at 0 degrees, its performance is down to 40 percent. Partially discharged batteries that do not start an engine when extremely cold, therefore, may do so if they are warmed up.

Why the Cold Makes Batteries Fail

    Since a battery has reduced ability to perform in adverse conditions, symptoms that do not present in warm weather can do so in the cold. A parasitic -- sometimes called a vampire -- drain, such as a warning light or alarm system, that does not affect the battery charge level in the warm, can drain it in the cold. An internal battery short that doesnt affect performance in the summer can do so in the winter. The cells in a fully discharged battery can freeze; if this happens, the battery will not take a full charge again and must be replaced.

    If the battery has never had a full charge because the alternator or generator is not functioning as it should, that partial charge may be adequate to start the engine in warm conditions. Making frequent stops and starts, such as a multi-store shopping trip, especially in adverse conditions that dictate heaters and headlights be used, can deplete a cars battery and not give it time to fully recharge.

Understanding Cold Cranking Amps

    The figure noted on a battery as a CCA value is a measure of its cold cranking amps; this is an industry term that defines that batterys ability to perform in cold conditions. It references the batterys ability to deliver at least 7.2 volts for 30 seconds at 0 degrees Fahrenheit. The greater the CCA value, the better it performs in cold conditions.

Preventative Measures

    It is not uncommon for vehicle operators in extremely cold places to remove the batteries from their vehicles at nighttime and keep them in heated indoor areas. Dedicated battery heaters are sold in regions susceptible to extreme cold; these plug into 110-volt outlets and warm the battery while the vehicle is not in use.

Jump Starting

    An entirely flat battery is not receptive to a jump start; this is why the two cars must be left connected by jumper cables for a few minutes before the running one can start the dead one. Batteries that appear dead because they are extremely cold, and thus cannot be jump started, can become receptive to a jump start if they are warmed first.

Paying It Forward

    Due to the performance percentage loss detailed above, even a fully-charged battery may not be able to provide sufficient current to start the engine in extreme cold. In this case -- in the opposite of what may seem obvious -- taking a little charge out of the battery can make it work. Switching on the headlights causes the battery to function; current passes through it and in doing so, creates some warmth. It may be that after a minute with the headlights on, the battery can turn over the engine.

Word of Caution

    Batteries contain acid, and they give off fumes that are both flammable and explosive in the course of normal operation. Artificially heating an extremely cold battery by any other method than moving it to a warm space could be dangerous. Never lower a cold battery into a tub of warm water, set it near a radiant heat source or use a hair dryer over the case.

Sabtu, 24 Oktober 2009

How to Test Lawnmower Coils

Lawnmower ignition systems work similarly to automotive systems; they're just a bit simpler and more compact. The mower coil is a two-in-one piece; a magnetic sensor on the back of the coil detects the passage of magnets on the flywheel, which sends a signal to the primary coil to fire the spark plug. Diagnosing a mower coil is just like diagnosing any other, as are some of the tricks that can save you valuable time and frustration.

Instructions

    1

    Remove the mower's plastic engine cover to access the spark plugs and plug wires. Disconnect the plug wires from the plugs and follow them back to the coil; you can find it mounted somewhere near the back of the engine crankcase, near the flywheel.

    2

    Pull the kill wire off of your plug. This thin wire acts as a ground for your coil when you hit the kill switch, rerouting energy from the coil into the frame instead of into the spark plugs. Pop an old spark plug into one of the plug wires. Hold the plug tightly to your engine block with a pair of insulated channel-lock pliers.

    3

    Have an assistant to attempt to start the mower as you normally would, and watch for a bright, thin, blue-white spark jump across the plug. You might want to perform this test in a dimly lit garage to best gauge the spark quality. If the spark is dim, thick and yellow-colored, then the coil isn't delivering the power it should and needs to be replaced. If there's no spark at all, double-check that you disconnected the kill wire. If the kill wire's disconnected and there's no spark, proceed to the next step.

    4

    Check the air gap between your coil's magnetic pickup tabs and the magnets on the flywheel. This gap needs to be narrow and precisely set. Manufacturer recommendations vary, but the gap should be between about 0.010 and 0.014 inch. If you don't have a set of feeler gauges, use a business card to measure the gap. Loosen the coil and adjust it as need be so that the appropriate feeler gauge or business card just fits between the tab and magnet. Re-test for spark.

    5

    Remove the plug wire from the coil output. Set your digital multimeter to read in thousands of ohms (1K with the Greek Omega symbol next to it), and touch one of the leads to the coil output. Touch the other lead to the power input terminal from the alternator or battery. Specs vary, but you should get an ohm reading somewhere between 3,000 and 5,000 ohms. If your meter reads an open circuit or (infinite ohms), or a short circuit (zero ohms), then it's time to replace the coil.

    6

    Switch your ohm meter to read in single ohms. Perform the same test; this time testing from the coil's ground terminal (the kill terminal) to the main coil output. Resistance in ohms should be very low, almost nonexistent. If you get more than 50 ohms your coil is bad.

Common Causes of Vacuum Leaks in 2005 VW Jetta

Volkswagen's fourth-generation Jetta isn't any more prone to vacuum leaks than any other car -- and probably a lot less than most. But little failures can and do happen, and the eight different engines offered with this car have their fair share of vacuum lines and potential leak points.

Vacuum vs Boost Leak

    Turbocharged engines have been a Jetta staple for many years now and the 2005 Jetta is no exception. Many Jettas left the Wolfsburg factory with VW's exceptional 1.8-liter four-cylinder turbo, which changes the air leak equation a little bit. With a normal vacuum leak, the engine will suck extra air in througha leaking hose -- or, more likely, hose fitting -- and the engine will run lean. Turbocharged engines have pressurized intake tracts, so leaks will result in air blowing out from the pressure generated under boost.

Leak Detection Pump

    Oh, those Germans -- they do think of everything. The Jetta depends on engine vacuum to perform dozens of different functions, not least of which to operate the brake booster and to keep rogue fuel vapors from leaking out of the car. It is for these reasons that the Jetta uses a supplemental vacuum pump that speeds vacuum buildup at startup, provides vacuum when called for and helps the computer to detect leaks. The pump kicks on whenever vacuum is lower than it should be; if the pump runs when the computer says it shouldn't, the computer will trigger a vacuum-leak warning code.

Vacuum Diagram

    All of the Jetta's different engines uses a unique vacuum tube arrangement, and VW was kind enough to assist you -- or their mechanics, anyway --in tracking them down. A sticker that details the location, routing and purpose of every vacuum line on the engine can generally be found on top of the radiator support of every Jetta. You'll refer to this diagram on a regularly when tracking down leaks; just go by the diagram and check line-by-line till you find the leak.

Tracking Leaks

    The computer may tell you exactly where to find the leak, depending upon its location and severity. But, if it doesn't then you can fall back on this old mechanic's trick: Pick a line on your routing diagram and trace it back to the engine. Have an assistant briefly start the car, and spray the line where it connects to the engine with a two-second burst of brake cleaner or ether starting fluid. If you hear the engine suddenly rise in rpm after spraying the connection, then you've found your leak. Keep working along the line, spraying every connection until you find the leak. When you get to the end of the line, pick another and start again.

How to Diagnose a Faulty Crankshaft Position Sensor

How to Diagnose a Faulty Crankshaft Position Sensor

The crankshaft position sensor monitors the rate at which your crankshaft is spinning. Though extremely durable, they can be damaged by high temperature fluids coming from the engine or by road debris damage. Your crankshaft position sensor may be faulty if your check engine light is on and your car is stalling---especially at low speeds---or stalls when you shift gears. Other symptoms include the engine misfiring and acceleration problems.

Instructions

    1

    Plug in your diagnostic scanner and check the fault codes.

    2

    Diagnose your problem from the fault code displayed on your diagnostic scanner.

    3

    Drive to a local automotive parts store for a less expensive alternative. Most of them have scan testers and will test (for free) your crankshaft position sensor and interpret the code.

The 1997 Suburban Won't Shift Out of Park

The 1997 Suburban Won't Shift Out of Park

If your 1997 Chevrolet Suburban won't shift out of park, it can leave you feeling like you're stranded. Fortunately you may be able to get going again without too much trouble and get home or get to a certified repair facility. The 1997 Suburban is equipped with a shift brake interlock that prevents the transmission from moving out of park unless the brake is pressed. If this system fails, the transmission will stick in park.

Instructions

    1

    Look in the driver's foot well and examine the brake pedal. There is a small switch on the brake pedal that controls the brake lights and the shift brake interlock. Sometimes this gets dirty and sticks in place. If this is happening, it will prevent the lock from triggering and releasing the transmission. Clean the switch and try to move the shifter again.

    2

    Inside the shift mechanism there is a solenoid that moves backward and forward. This also has a tendency to become stuck when it gets dirty. Its position on the column makes it particularly vulnerable to spilled soda and coffee. Pop the plastic cover off the shifter using your fingers around the edge and clean the underside and the shifter workings with the solvent cleaner. Test the mechanism again. If it is working you will hear a clicking sound from the column when the solenoid releases.

    3

    Put the key in the ignition and turn it one click from the "Lock" position to the "Off" position. If the dash lights come on, you have gone too far. Press the brake and move the transmission from park to neutral. You can start and drive the vehicle with the transmission in neutral, but you have to use the parking brake to keep the car still.

Jumat, 23 Oktober 2009

How to Troubleshoot Engine Problems on a '94 Isuzu Rodeo

The 1994 Isuzu Rodeo came equipped with a 2.6-liter four cylinder engine. It also included many different standard features such as power brakes, a rear window defroster, styled 15 inch steel wheels, tinted glass, a five-speed manual transmission, rear wheel anti-lock brakes, cloth seating, a front bench seat and power steering. Because the Rodeo is made up of so many different parts, systems and components, it can be challenging to troubleshoot a problem with the vehicle's engine. Two ways to find a problem is to examine manufacturer recall information to see if it matches up to the issues you are having and to look at general troubleshooting tips and techniques.

Instructions

    1

    Check the camshaft seal end plug inside the engine of your Rodeo if you see oil leaking underneath the front part of the vehicle. Over time, the constant expansion and contraction of the cylinder heads inside the engine block can cause the camshaft seal end plug to become dislodged from the cylinder head. This problem can allow engine oil to be begin to leaking out from the camshaft. If the engine oil comes into contact with an ignition source a fire could start inside the Rodeo's engine. Take the vehicle to a local Isuzu dealership to have camshaft seal end plug retainer plates installed on the plug.

    2

    Look at the radiator hoses inside your Rodeo's engine when it feels like the vehicle is overheating as you drive. One or more of the hoses could be cracked, leaking or ruptured. The head gasket inside the engine may be leaking or the thermostat may be stuck closed improperly. You may also have other problems with your radiator system, including a worn or damaged radiator cap, a radiator fin obstruction, a non-functional radiator fan motor, a missing radiator fan blade or a faulty cooling fan switch. You should also check the water pump belt to ensure that it is still attached and functioning properly and the intake manifold gasket to see if it has become worn or damaged.

    3

    Inspect the oil pump inside your engine if you have low engine oil pressure. The pump itself could be worn out and in need of replacement or the oil pump cover could be bent or cracked. The oil pressure switch may be loose, worn or poorly connected or your oil filter may be clogged or worn out.

Kamis, 22 Oktober 2009

Transmission Sticks When Changing Gears

Transmission Sticks When Changing Gears

The transmission is part of your vehicle's drive train and is responsible for the forward and rearward motion of your automobile. Whether your transmission is automatic or manual, it can develop problems that could cause it to stick when changing gears. Understanding the potential problems can help you avoid expensive repairs down the road.

Valve Problems

    In your car, fluid pressure or electrical solenoids push transmission fluid through valves that open and close based on computer signals from the transmission control module. Unfortunately, the valves can become worn and begin to stick, stopping the fluid from moving through smoothly. This causes the transmission to catch when changing gears, requiring you to replace or repair the worn parts.

Transmission Fluid Problems

    Burnt or worn out transmission fluid can also cause the transmission to stick when changing gears. Transmission fluid should be a blood red color with a sweet smell. If it is black, yellow, orange, clear or smells burnt, it is probably worn out or dirty. You can solve this problem by replacing the transmission fluid. In fact, it's best if you change this fluid regularly since waiting too long can damage mechanical parts and lead to more expensive repairs.

Clogged Transmission Filter

    A clogged transmission filter can cause problems with changing gears because it will not allow the fluid to pass through the valve body or valve solenoids at the proper pressure. Without pressure, the plates won't move properly and you won't be able to easily change gears. This can be symptomatic either by itself or along with burnt or worn out transmission fluid, and both should generally be replaced at the same time, rather than just replacing one or the other.

Damage to Pressure Plates

    The plates in the transmission that actually change the gears can have lost friction material or damage. These plates will rub against each other, making it difficult or impossible to change gears. Usually, your only option for fixing this problem is to rebuild or replace the transmission.

How to Troubleshoot a 2002 Dodge Grand Caravan

The Grand Caravan is a minivan manufactured by the Chrysler Group since 1983 and is currently still in production (as of 2011). According to research from automotive repair websites, as well as TSB and NHTSA reports, the most common issues with the 2002 Dodge Caravan are found in the HVAC system, suspension, ignition and fuel tank. When troubleshooting the Caravan, thorough inspection of these areas is highly recommended.

Instructions

    1

    Check for odors coming from the air vents. If you detect moldy or musty aromas, clean any bacterial residue from the evaporator using cleaner and disinfectant.

    2

    Check beneath the vehicle for any leaking coolant. If found, check the underbody hoses to determine which, if any, are leaking. Replace any leaking hoses.

    3

    Listen for rattling noises while driving at low speeds. If present, replacing the front struts typically solves this issue.

    4

    Check beneath the fuel tank for leakage. This is typically due to a malfunctioning rollover valve or fuel tank gasket. Replace as necessary.

How to Troubleshoot a Mallory Unilite Distributor With No Spark

When a Mallory Unilite distributor fails to produce a spark to the plugs, the vehicle will not run. The Mallory Unilite distributor uses an infrared light lens and a sensor between which a wheel with tangs, called shutters, passes. The infrared light makes a completed circuit when the sensor picks it up. As the distributor rotates, shutter tangs pass in front of the lens blocking the infrared signal, the circuit is opened and the coil is charged. When the shutter passes, and the signal is restored, the coil is fired discharging its voltage through the plug wires.

Instructions

    1

    Locate the coil, which will always be close to the distributor, and see if it is a 12- or 6-volt coil. All vehicles need a coil, which acts like a capacitor to build enough electrical energy to fire the spark plugs. The distributor simply directs the spark to the proper cylinder. Many coils are 6-volt and need a ballast resister installed in the power line to the coil. If a 6-volt coil is used without the resister it will eventually overheat. If it is a 6-volt coil, check the coil side of the resister for voltage with the key on. Place the black ground voltmeter lead on a good ground on the engine and probe the coil side of the resister. It should be the target voltage of 6 volts. If not replace the resister.

    2

    Check the positive side of the coil for the proper voltage, be it 12 or 6 volts. Repair the wiring if the voltage is not correct. Move the red probe to the negative terminal of the coil. The voltage should be the same. If not replace the coil.

    3

    Remove the distributor cap and pull off the rotor. Inspect the carbon secondary button in the center of the cap for severe wear or irregularities. Replace the cap if the button is missing or worn.

    4

    Place the red lead on the negative terminal on the coil. Place a credit card between the infrared light and the sensor. The voltage must drop below 3 volts. This is imperative. If the voltage does not drop below 3 volts replace the Unilite module. If the voltage does not rise back to 12 volts at the coil negative terminal once the card is removed, replace the module.

How to Diagnose a Squeak When a Truck Is Backing Up

How to Diagnose a Squeak When a Truck Is Backing Up

A small, seemingly innocuous squeaking sound can become a large annoyance that plays upon your expectations every time you operate your vehicle. Though it's probably harmless, you still want it to go away --- now. The situation can become especially tiresome in a commercial vehicle, such as a large truck. These vehicles back up many times during one day as they go about their intended tasks. Learn to diagnose that pesky squeak and, if possible, take the proper steps to eliminate it.

Instructions

    1

    Inspect the frame-to-body mounting bolts. Check to ensure they are all present and tight. Loose frame-to-body bolts will allow the body or frame to shift slightly upon backing up, creating noise.

    2

    Inspect the condition of the suspension bushings. Spray them with silicone spray to restore their pliability and eliminate squeaks.

    3

    Inspect the braking components. Check to determine whether the emergency brake system is releasing properly. A dragging brake shoe in a drum brake configuration will cause squeaking noises in and around the wheels.

    4

    Inspect the driveshaft and U-joints. Worn U-joints can cause clunking and squeaking sounds under the truck.

Rabu, 21 Oktober 2009

What Does It Mean When Your Car Says "Fuel System Lean?"

While the onboard diagnostics systems pioneered during the 1980s performed admirably for their time, computer diagnosis really only came into their own with the introduction of the standardized Onboard Diagnostics, Series Two in 1996. OBD-II monitors almost every aspect of engine performance, with the most important being crankshaft position, throttle position and exhaust gas temperature. A "lean engine" code can prove disastrous if left unaddressed, so you need to deal with it as quickly as possible.

Lean and Rich

    All chemical reactions have a limiting reactant, or a reactant that runs out before the others. In an engine, oxygen is the limiting reactant to combustion, since air is a lot more difficult to get into the engine than fuel. Manufacturers typically inject more fuel than the available oxygen can burn because the unburned fuel helps to keep combustion chamber temperatures down. If fuel becomes the limiting reactant, then temperatures inside the engine skyrocket and the entire system stands in danger of melting.

Sensor Construction

    Oxygen sensors are available in several types, but most vehicles use a Lambda-sensor design. The O2 sensor has three parts: a conductive electrical plate exposed to the exhaust, a second plate exposed to the outside air and a piece of zirconium dioxide sandwiched between them.

How an O2 Sensor Works

    Zirconium dioxide (also known in a slightly different form as cubic zirconia) acts as a sort of chemical generator; when one side of the zirconia gets hotter than the other, it releases energy in the form of an electrical voltage. The computer reads this voltage and uses it to extrapolate the amount of heat (and thus oxygen) present in the exhaust stream.

Causes

    A lean condition is always the result of a deficit in fuel (clogged injectors or filter, low fuel pressure), an excess amount of air (generally from a vacuum leak) or a bad oxygen sensor. If the engine runs fine otherwise, then odds are that the O2 sensor has gone bad and needs replacing. This is especially true if the lean code comes hand-in-hand with a drop in horsepower and a loss in fuel economy. When the computer stops trusting the O2 sensor, it goes into an "open loop" computer program that injects more fuel to keep the engine from melting down.

BMW 840 Start Problems

BMW 840 Start Problems

The BMW 840 manufacturer recalled more than 400,000 vehicles because of problems with the throttle that created starting problems. The manufacturer also published technical service bulletins (TSB) that concerns starting problems some BMW 840 owners are experiencing. Other consumer complaints are recorded on some automobile review and reports websites. These also report starting problems with this BMW model.

Throttle Problems

    The BMW 840 was recalled for throttle cable problems that create starting problems. The cruise control cable and throttle cable is attached to the same throttle valve lever, one that reportedly causes the cable to break under normal driving conditions. Vibration and environmental conditions cause the cables to break. Once the cable breaks, the throttle does not work properly, preventing the BMW 840 from starting.

Fuel System Problems

    A published TSB on the BMW 840 concerns fuel problems that are affected the carburetor, creating starting problems. The intake air system leaked, preventing a continuous flow of fuel into the carburetor. This created starting problems in the BMW because air pockets are getting into the fuel line that leads to the carburetor.

Intake Manifold Leaking

    The intake manifold leaked on the BMW 840 engine, creating starting problems in the automobile. Once a leak develops in the intake manifold, air is allowed into the cylinder and the BMW begins to misfire, cough or not start. The gasket on the intake manifold will be damaged and needs replacing.

Cylinder Bore Erosion

    According to The Sunday Times in London, England, some BMW 840 owners reported cylinder bore erosion. This erosion prevented the pistons from pushing up and down smoothly, creating starting problems on the BMW. The erosion problems were attributed to the materials used in producing the engine block, as well as debris entering the cylinders causing damage to the bore.

Senin, 19 Oktober 2009

How to Disable the TPMS in GM Vehicles

How to Disable the TPMS in GM Vehicles

The U.S. Department of Transportation has mandated that all vehicles manufactured after 2008 include a tire pressure monitoring system (TPMS). Although you cannot disable the TPMS in a General Motors (GM) vehicle, you can reset the system if you recently checked your tires and inflated them properly. If you do not adequately inflate the tire, however, the TPMS trouble light will remain on.

Instructions

    1

    Start the GM vehicle.

    2

    Locate the lowercase "i" button on the driver's information panel. It is located to the right of the steering wheel. Press the button multiple times to access the TPMS system, and identify the specific tire that is triggering the dashboard trouble light.

    3

    Press the reset button on the driver's information panel. This button features a check mark, and is at the lower end of the panel. If this does not work, press and hold down the "i" button and then press the reset button.

Minggu, 18 Oktober 2009

How to Check a Carburetor Float

How to Check a Carburetor Float

Although many people consider carburetors to be simpler than fuel injection, a lot of things have to operate correctly and in sequence for a carbureted vehicle to even run, let alone run well. When fuel enters a carburetor, it flows into a small cavity called a float chamber or bowl. The flow of fuel is controlled by a valve known as a needle and seat, which is attached to a float. As gas rises or falls in the float chamber, the float moves with it, opening and closing this valve. A number of things can go wrong with the process, causing all sorts of problems, including poor idle, stalling or not starting at all.

Instructions

    1

    Remove the top of the carburetor. Keep track of all screws and their positions. Depending on type, the float or floats will either come off with the top and dangle, or are mounted in the carburetor body. Carefully turn the carburetor top upside down on the top-mounted variety so as not to damage the delicate float mechanisms.

    2

    Examine the floats for any obvious damage and the float chambers for signs that the floats have been rubbing on the sides. Check the float operation by gently lifting with a finger to make sure nothing sticks or binds.

    3

    Remove the pins that hold the floats. Carefully remove the floats. The needle valves will usually come out as well, so check them for wear at the tips, then be sure to slip them off the float tangs and put them back into the seats for safekeeping.

    4

    Hold a float next to your ear and shake it. If you hear gas inside, the float has an obvious leak. Reveal less-obvious leaks by grasping the float by the tang with a pair of pliers and submerging it into a pan of very hot water. A stream of bubbles will also indicate a leak. Leaking and gas-saturated floats must be replaced or repaired.

    5

    Install a new carburetor top gasket. Reinstall the floats, making sure you engage the wire hangers on the needle valves. Check the float action again to make sure they move freely.

    6

    Consult the specifications for your carburetor type. Check and adjust the float height using the adjustment tool or a small steel rule. Reassemble the carburetor and check for proper operation.

How Many Oxygen Sensors Are in a 2009 VW Jetta?

Look at the hind quarters of the first-generation Jetta, and you might notice that the bottom of the rear window seems oddly low next to the top of the trunk lid. This little styling quirk stuck with the Jetta all the way up to 2005, but it wasn't because the lower window enhanced visibility. No, this misalignment was due entirely to the fact that in order to create the car, VW just replaced the Golf hatchback's rear hatch cover with fixed glass and a protruding cargo box. Leave it to the Germans to turn a tacked-on trunk a trademark styling cue.

Oxygen Sensors

    In the American market, the 2009 VW Jetta came with three different engines. The base engine was a 170-horsepower, 2.5-liter, inline five-cylinder powerplant; GLI models got a 200-horsepower, turbocharged 2.0-liter, and the newly reborn Jetta TDI got a 140-horsepower, direct-injected four-cylinder diesel. Regardless of the engine, all used a pair of oxygen sensors: one at the exhaust manifold, and a second in the pipe, just after the catalytic converter. If you get an O2 sensor fault code, Sensor 1 is the upstream sensor on the exhaust manifolds, and Sensor 2 is the downstream sensor, after the converter. On 2.0-liter engines, the downstream sensor is screwed directly into the catalytic converter.

How to Troubleshoot a BMW 325 Series

The 2006 model year was the last time BMW produced its 325i as part of its "3 Series." The 325 line included a coupe, a sedan, a wagon and a sedan. The 325i owner's manual gives drivers all the information they need to troubleshoot and repair basic problems with their BMWs.

Instructions

    1

    Use the right type of fuel. Using the wrong type of gas can damage the vehicle's catalytic converters or cause a "knocking" sound in the engine. The 2006 BMW 325i owner's manual reminds drivers to use unleaded fuel in their vehicles and recommends an octane of at least 91. Fuel with an octane of 93 is also permissible. Do not overfill the gas tank, which has a maximum capacity of 16.1 gallons.

    2

    Maximize your 325's fuel efficiency by keeping the tires properly inflated and aligned. If you've noticed a drop in your miles per tank, use a tire gauge to measure the pressure in all four tires. The recommended reading in pounds per square inch, or psi, will vary based on the type of tires installed on your 325i; page 110 of the owner's manual lists the exact tire pressure recommendations for a wide range of BMW tires.

    3

    Pop the hood of your 325 series to familiarize yourself with the different parts of your engine. Focus on these three locations: the expansion tank for coolant, located behind the front passenger-side headlight; the jump starter connection, located just below the windshield on the passenger side of the vehicle; and the filler neck for engine oil, located about halfway between your front bumper and the windshield on the passenger side of the vehicle.

    4

    Check your 325's engine oil level regularly. While the 325 series is equipped with an electronic sensor and alert system, which will display a message on your dashboard when the level is too low or too high, sometimes this sensor can malfunction. If the dashboard indicator says the level is too low, remove the cap on the filler neck and add a small amount of engine oil until the light turns off on its own (BMW recommends using high-performance synthetic oil). If the indicator says the level is too high or that the system is inactive, take the vehicle to a certified BMW repair shop to work on the system.

    5

    Add extra coolant to your vehicle when necessary. Coolant helps your vehicle operate at an acceptable temperature; if you notice the engine temperature gauge on your dashboard operating at "high" at all times, you may be running low on coolant. Slowly loosen the coolant cap but don't remove it; this will give the tank time to release pressure gradually. Check to see that the coolant level is below the minimum and maximum level on the dip stick; if it is too low, add enough coolant so that it is properly filled. Even though coolant is made up partly of water, which can evaporate, you may still want to have your system checked for any leaks.

    6

    Recharge a dead battery by jump-starting it with the help of a second vehicle. Turn off both vehicles completely, then connect one positive (red) clamp on your jumper cables to the positive terminal on the assisting vehicle. Connect the second positive clamp to the "positive" port located near your 325's passenger-side windshield. Next, connect one negative (black) clamp to the negative terminal on the assisting vehicle and the second negative clamp to the "negative" port located on the far passenger-side under your 325's hood. Start the engine of the assisting car, giving it a few minutes to warm up before turning on the engine of your BMW. Take your 325 to a repair shop as soon as possible for a new battery.

Sabtu, 17 Oktober 2009

How to Troubleshoot a Knocking Noise in a 1999 Chrysler Minivan

Chrysler's mechanics were caught a bit off-guard when engineers delivered the company's first purpose-built, front-drive V-6 engine. Expecting a high-tech, dual-overhead-cam beast in the mold of the Ford Taurus SHO, they instead got an old-school pushrod engine like the standard Taurus. Still, the Chrysler 3.3-liter and its 3.8-liter derivative exceeded expectations, providing performance and economy belying their simple natures. But the 60-degree V-6 was still a fairly unsophisticated powerplant at heart, and even when new it wasn't exactly the quietest or smoothest engine out there. A decade of wear certainly hasn't improved that condition any.

Keeping an Ear Out

    Odds are good that your ticking problem is coming from the engine, but explore other options before tearing in. An engine ticking problem will typically manifest at idle, either getting better or worse as rpm or engine temperature goes up. If you only hear the ticking noise when the minivan is moving, then you might have any number of drivetrain or chassis issues. A medical-type stethoscope and an assistant are invaluable here. As you drive down the road, determine the conditions under which the ticking happens, duplicate them, and have your assistant press the stethoscope cup to the minivan's body, floorboards and wheel-wells as you go. Fortunately, a minivan is large enough that you can maneuver around inside easily, and get within inches of the suspension and drivetrain on the other side of the sheetmetal.

Possible Chassis Sources

    If the ticking gets louder or quieter as you go around a corner, then listen to the body as close to the wheels as possible. Odds are reasonable that you have a bad wheel bearing, or a cracked, loose or bent suspension or steering component. If you suspect a bad bearing, jack the minivan up and try to wiggle the wheels up and down by hand; if they move a noticeable amount, then you have a bad bearing. Check the steering and sway bar end links afterward. Loose lug nuts or wheel weights are also a possibility. If the vehicle knocks under acceleration or deceleration, but the noise isn't directly tied to engine rpm, then you may have one or more bad CV joints.

A Screwdriver to the Ear

    You can track down engine noises with a stethoscope, but a long screwdriver is safer and easier in a cramped engine bay like that on a minivan. Push the tip of the screwdriver against your target area -- the engine block, timing cover, valve covers, et cetera -- and nestle the end of the handle into your ear, or under your ear, against the jaw bone. Sound and vibrations will travel up through the screwdriver, and will enter your ear canal, or will transmit to your ear drum through your jaw bone. The ear is a better location for listening for deep, low-frequency knocks; the jaw is better for light, high-frequency taps.

Tapping at Idle -- Excess Lash

    This has been a known problem with 60-degree V-6 engines for some time now -- enough so that Chrysler issued a technical service bulletin on it in 1998. This sound, which might range from a light tap to a medium knock, depending on the engine, happens when the engine is fully warmed up and idling between 500 and 1,000 rpm. Place your screwdriver tip on one of the valve covers and listen; if the noise goes away over 1,000 rpm, then there's a good chance that you'll need to adjust the valve lash. This procedure might be best left to a professional. That's a somewhat expensive proposition, but it's not the worst case scenario.

Valvetrain Tapping -- It Gets Worse

    Over time, using the wrong oil, consistently low oil levels, or using cheap aftermarket oil filters without the required anti-drainback valve will starve the lifters of oil for some time after the engine starts, resulting in valvetrain noise for the first minute of operation. You'll hear this tapping loudest when you listen around the base of the intake manifold. This is exacerbated by the fact that the lifter oil holes are very small and prone to clogging with oil sludge; combined with camshaft wear or low oil pressure, this will cause the lifters to remain collapsed and continue tapping long after the engine warms up. Consistent low oil pressures or levels will also cause cam bearing failure, starving the lifters of oil and causing tapping.

Valvetrain Tapping -- And Worse

    The worst case scenario for the valve train is a broken rocker shaft support, which will manifest as a deep tapping or knocking and a loss in engine power. The rocker supports on earlier 60-degree V-6 heads are fairly weak, and are known to crack and fail. The only "real" fix is to replace the cylinder head. However, drilling out the rocker shaft support hole in the head and inserting a "helicoil" will allow you to use a longer bolt, reattaching the rocker and getting the vehicle running.

Timing Chain and Oil Pump

    The clearance between the timing chain and the timing chain cover on these engines is very narrow -- even normal amounts of timing chain stretch will send the chain rattling and scraping against the inside of the chain cover. This is very common on older engines, and not particularly dangerous except as a sign that the chain's slightly stretched. Noise from a malfunctioning oil pump is equally common, and generally results from following Chrysler's -- wildly optimistic -- 7,500-mile oil change interval recommendation. The oil pump is very close to the timing chain behind the front cover, so it can be very difficult to tell the difference between a bad pump and a bad chain. A bad pump will exhibit more of a pronounced tap or knock, though, compared to the chain's lighter, scraping tap.

Very Bad Things

    Diagnosing a bad oil pump is critical, because oil pressure is critical on this engine. Engine-killing rod knock is very common on engines that experience very low, consistently low or fluctuating oil pressure. That's particularly true in this case, because the thrust bearings that keep the crankshaft in place are known to wear out before the rod and main bearings. Without a thick layer of pressurized oil to keep things in place, the rotating assembly winds up flopping around inside the block, causing lots of bad things to happen. Don't panic if you hear what sounds like rod knock, though; it might be a cracked flexplate. That's not a great deal better, but it is a bit. Rod knock will rise or fall in frequency linearly with rpm, and will generally get louder as rpm goes up. This may have as much to do with falling oil pressure as anything else. Rod knock is generally deep and hard enough that you can feel it when you put your hand on the intake manifold; cracked flexplates exhibit more of a loud, auditory tapping or popping.

Oil Treatments and Flushing

    You've probably noticed that a lot of this engine's issues come down to the oiling system. You might be inclined to completely flush the system to clean it out and rid it of any deposits, and that's not necessarily a bad idea if the knock is coming from your valvetrain. Aggressive oil flushes contain a lot of solvents, which will break down deposits in the engine and do a fine job of turning new oil into thick, black sludge in less than a hundred miles. In this case, though, the engine might already have experienced enough wear and damage from oiling issues that thinning it and sending sludge through the system may prove catastrophic. Instead, you should change the oil, add a 1/4-dose -- about 1.5 ounce for every four quarts of oil -- of "Seafoam" type cleaner, and change your oil again in 100 miles. Repeat this two or three times to gradually clean the sludge out of your system, while listening to hear if the knock worsens or gets better. Then switch to a high-quality 5W-20 synthetic oil.

Jumat, 16 Oktober 2009

How to Manually Error-Test My Ford Truck

How to Manually Error-Test My Ford Truck

Not all Ford trucks can be manually error-tested. After 1996, the second generation of On-Board Diagnostics became standardized for all car and light trucks. Accessing the OBD-II system requires diagnostic hardware. The error codes themselves are alpha-numeric, which is logistically difficult to flash through the truck's check engine light. Manual code retrieval works only for Fords using Electronic Engine Control-Fourth Version. Those vehicles run from 1983 to 1995. Still, the process is not that complicated, and the codes can be retrieved in less than 15 minutes.

Instructions

    1

    Warm up the Ford truck's engine. You can either let the vehicle idle, or you can drive it around. Either way, the engine needs to be truly warmed, which means the air conditioner needs to stay off.

    2

    Turn the engine off and release the Ford's hood. Prop the hood open and look for two outlets towards the rear of the engine, near the fire wall. One outlet features six sides and six slots. It is called the Self-Test Outlet. Next to it, you will find a single slot on a twisted braid of wire. That is the Self-Test Input.

    3

    Connect the STI and the STO with a length of jumper wire. Place one end of the wire into the STI. Place the other end into the STO's grounding slot, which should be located in a row of four openings. The slot you need is the center-left.

    4

    Return to the Ford truck's driver seat. Place your key into the truck's ignition and turn to "On." Leave the engine off. This will initiate the EEC-IV self-testing procedure. Grab a pen and a slip of paper and keep your eyes focused on the check engine light.

    5

    Count how many times the Ford truck's check engine light goes on and off. This will represent a two-digit EEC-IV fault code. The first number will be conveyed through long flashes. The second number will be conveyed through shorter flashes. For instance, EEC-IV code 24 is two long flashes and four short flashes. Write the code numbers down.

    6

    Turn off the Ford truck's electrical system once the system has cycled through all the error codes. Remove the jumper wire from the STI and STO. Close the hood over the engine.

    7

    Look up definitions for all of the codes you have written out. Ford's EEC-IV codes are not in the owner's manuals. You can locate definitions in a Haynes manual or online. These definitions will give you an indication of what repairs are needed. If you choose not to complete the repairs, bring the truck and code list to your mechanic. It should keep you from being charged diagnostic fees.

Causes of a Radiator Leak

Causes of a Radiator Leak

Radiators keep a vehicles essential parts cool. They allow the engine to function properly and prevent overheating whether a vehicle is idling in traffic or running a long distance without stopping. When the radiator leaks, vital coolant seeps out and thus the system cant cool the vehicle as efficiently. Worse, these leaks can sometimes result in overheating and severe damage of the engine. Many varying factors can lead to radiator leaks.

Corrosion

    Theres a reason mechanics recommend that people clean their cars after a deep snow. Road salts and other materials can collect on a radiator and corrode the metal, eventually leading to a leak. Once this happens, a mechanic must either patch the leak or replace the radiator entirely.

Freezing

    If a radiator hasnt been filled with appropriate coolant, or worse, has been filled with water, it can experience severe damage at freezing temperatures. Water expands as it freezes and can break many materials in the process, including a radiator. Always fill a radiator with antifreeze to help prevent this cause of leakage.

Puncture

    Road debris, stones and other trash may sometimes get caught on the underside of a car and puncture various components, especially at high rates of speed such as those on interstates and freeways. Human error can also result in punctures in various situations. Mechanics can successfully patch some punctures, while more severe punctures will ruin a radiator completely.

Age

    As time goes by, radiators will experience the wear and tear of use, just as with any mechanical part of a vehicle. Internal components may begin to leak, hoses may break down and tiny cracks may develop within the radiator. When a radiator begins to experience leakage due to old age, it may be time to replace it.

Weak Radiator Cap

    Radiators work within a pressurized environment, so if the external radiator cap has any damage, it will leak coolant every time the vehicle operates. An improperly sized cap would also produce the same result. A pressure test will determine if a radiator cap is the culprit.

Kamis, 15 Oktober 2009

How to Check the VTEC Oil Pressure Switch

The oil pressure switch in your vehicle measures the integrity of the engine's lubrication system -- it warns you when it detects a problem. If the oil pressure switch is not functioning properly, however, you may remain unaware of additional mechanical problems. It's imperative to ensure a proper connection between the oil pressure switch and the engine control unit. An improper connection will result in a malfunctioning oil pressure switch. Verify that a problem, which may seem related to the oil pressure switch, isn't actually caused by low oil levels or a clogged filter.

Instructions

    1

    Ensure a secure connection between the red wire to the oil pressure switch and connector "B5" on engine control unit "B."

    2

    Check the oil level in your vehicle. If the oil level is low, replace missing oil.

    3

    Check for a clogged filter, which may cause a drop in oil pressure. Remove the O-ring gasket and its attached filter from the VTEC solenoid valve assembly. Rinse the filter to remove dirt and debris, and then return it to its place on the solenoid valve assembly.

    4

    Connect the black harness lead on the pressure switch to the chassis ground. Check for continuity. If you do not observe continuity, replace the oil pressure switch.

How Can I Tell I My Manual Locking Hubs Need to Be Replaced?

How Can I Tell I My Manual Locking Hubs Need to Be Replaced?

Manual locking hubs have been around for at least 60 years. Originally invented by Warn Industries, manual locking hubs offer decreased driveline wear, increased fuel economy and smoother vehicle operation. Manual locking hubs, as the name implies, must be locked and unlocked by hand. When unlocked, they disconnect the front wheels from the rest of the vehicles' driveline. This allows the front wheels to "freewheel" without resistance. When locked, they reconnect the front wheels, ensuring that the vehicle operates as a true four-wheel drive.

Instructions

    1

    Locate the locking hubs on your vehicle. They are located at the center of the front wheels.

    2

    Inspect the hubs for any signs of oil seepage. If any is found, the internal hub gasket should be replaced.

    3

    Turn the hubs manually, back and forth, from the "locked" to the "unlocked" position. The hubs should turn freely throughout their range. If they seem to bind or grab, an internal cleaning is warranted.

    4

    Have a friend operate the vehicle, slowly, with the hubs locked. Stand beside the vehicle and listen for any grinding noises from the hubs. Do this with both hubs. A locking hub that has failed will often make a grinding noise as it slips in and out of position.

    5

    Operate the vehicle with the hubs locked and four-wheel drive engaged. If the four-wheel drive is not working and the front drive-line is turning, the problem lies in the manual locking hubs.

How to Tell If a Catalytic Converter Needs to Be Replaced

How to Tell If a Catalytic Converter Needs to Be Replaced

When your engine runs rich, it produces too much carbon dioxide (CO2). Catalytic converters take that CO2 and convert it into less harmful exhaust emissions. When converters plug up due to engine overheating, compression leaks or spark plug misfires, unburned fuel is emitted through the exhaust and into the air; hydrogen sulfide produces that rotten egg smell that tells you that your catalytic converter may need replaced. Measuring the intake vacuum or exhaust backpressure can help you determine whether your converter needs replacement.

Instructions

Checking Intake Vacuum

    1

    Connect the vacuum gauge to the intake manifold's vacuum port.

    2

    Idle the engine. Write down the vacuum gauge reading, which should fall between 18 and 22 Hg.

    3

    Rev up the engine speed to about 2,500 rpm and maintain it. The vacuum reading will fall, then rise to within a few Hgs of the idle reading. Consistently low readings and readings that continue to fall as the engine runs indicates possible backpressure buildup.

Exhaust Backpressure Checks

    4

    Connect the pressure gauge to the exhaust system by either removing the oxygen sensor and attaching the gauge to the exhaust manifold hole, or removing the air check valve to connect the gauge.

    5

    Start the engine and write down the backpressure reading. "Normal" backpressure varies between near zero and 1.25 psi at idle.

    6

    Accelerate quickly to 2,500 rpm. The pressure should measure between 1.25 psi and over 4 psi. If the reading exceeds 8 psi, assume there's a problem or blockage that needs further diagnosis.

    7

    Visually inspect the muffler and all exhaust pipes. If any are damaged, the problem might not be the catalytic converter.

Rabu, 14 Oktober 2009

My 1999 Chrysler 300M Won't Start

My 1999 Chrysler 300M Won't Start

Chrysler introduced the 300M in 1999 and ceased production on the vehicle after the 2004 model year. The 300M features a 3.5 liter, six-cylinder engine that function on standard ignition principles. Depending on whether the engine cranks or doesn't crank, there are standard items to check when it fails to start. These items are related to the vehicle's ignition and fuel delivery systems and should be checked before taking more involved steps.

Instructions

The 300M's Engine Doesn't Crank

    1

    Connect the 300M's battery to a functioning vehicle's battery using jumper cables and attempt to jump start the car.

    2

    Idle the 300M's engine for 15 minutes if the jump start is successful.

    3

    Remove the jumper cables and turn off the 300M's engine. If the engine fails to start back up, the battery can no longer hold a charge and needs replacing.

    4

    Consult a qualified mechanic to inspect the starter and ignition switch if jump starting the 300M is unsuccessful.

The 300M's Engine Cranks

    5

    Remove and inspect each spark plug with a spark tester, replacing any that are found to be defective.

    6

    Ensure that there is adequate fuel in the gas tank to start the vehicle.

    7

    Turn the key all the way to the right without cranking the engine. Listen for the fuel pump to pressurize when the car's electronics power on. If you hear no sound, the fuel pump may need to be replaced.

    8

    Remove the timing belt cover and inspect the timing belt to ensure it is adequately seated and is structurally intact. Consult a qualified mechanic to replace the timing belt if it is found to be faulty.

Selasa, 13 Oktober 2009

How to Reset a Jetta Transmission

The transmission in a Volkswagen Jetta contains a large number of electronic components. These components are controlled by a stand-alone computer called the transmission control unit, or TCU. When the TCU senses a problem with the transmission, it stores a diagnostic trouble code, or DTC, in its memory. It also illuminates the "Service Vehicle" light on the dashboard. Clearing the DTC from the TCU's memory resets the transmission and turns off the "Service Vehicle" light on the dashboard.

Instructions

    1

    Shift the Jetta's transmission into park or first gear (on a manual) and turn off the engine. Turn the ignition switch to the "ON" position.

    2

    Connect the data cable of an automotive scan tool to the Jetta's 16-pin diagnostic data port, located underneath the dashboard on the driver's side of the vehicle. Power on the scan tool.

    3

    Use the arrow keys on the scan tool's main menu to navigate between menu options. Choose "TCU" from the main menu.

    4

    Select "Clear all current and stored DTCs" from the TCU menu. Wait while the scan tool clears the codes. Disconnect the scan tool from the vehicle and start the engine. Confirm that the "Service Vehicle" light is not on. If the "Service Vehicle" light is off, the transmission has been reset.

How to Check a COP Coil

Coil on plug ignitions work just like any other kind of ignition. They just make do without plug wires leading from the coil output to the spark plug. COP ignitions rose in tandem with electronic fuel injection and computers fast enough to provide spark information in real time to multiple coils. Testing a COP coil is simple, requiring only the most basic of hand and electronics tools.

Instructions

    1

    Remove the car's engine cover and unbolt the coil assembly from the valve cover. Unplug the wiring harness leading to the coil, noting, if possible, the locations of the red and white, or dark and light, wires. The red or light wire should correspond to the positive terminal. The black or dark wire should indicate the negative.

    2

    Set your digital multimeter to read single ohms of resistance (indicated by the Greek Omega symbol) in the single ohm setting. Testing resistance in the coil will tell you if it's experiencing an internal short or open circuit that will impede function.

    3

    Place your red probe tip on the positive coil terminal and your black probe lead on the negative terminal. Manufacturer specifications will vary, but resistance across these terminals should read in the single digits or lower, probably below 1.0 ohms. If you get a reading in the hundreds of ohms or higher, then the coil is shot.

    4

    Set the multimeter to read in thousands of ohms. Poke the black probe tip up into the coil output where the spark plug would normally go, and put the red probe tip on the positive terminal where it was for the last test. You should get a reading of 5,000 to 10,000 ohms (5.0 and 10.0 if you're reading it in thousands). Some "segmented" coils might read as high as 15,000 ohms. If you get a reading that seems suspiciously high or low -- 4 ohms or 40,000 ohms -- or your tester indicates infinite ohms, the coil is dead.

How to Rebuild 6 Volt Lead Acid Batteries

How to Rebuild 6 Volt Lead Acid Batteries

Six volt lead-acid batteries consist of three cells each producing 2V and are wired in series. Lead-acid batteries, unlike other rechargeable batteries such as nickel cadmium or lithium ion, contain wet-cells. Each cell has two lead plates and is filled with sulfuric acid which burns on contact with clothes and skin. As a result, a full rebuild for a lead-acid battery is not a DIY job and should only be undertaken in an environment built for this purpose and by using the special equipment for this kind of work. It's best done by a professional wearing the appropriate protective clothing. However, if your lead-acid battery isn't taking or holding a charge you can safely rebuild the cell structure. The process isn't a guaranteed fix, but it is always worth trying before getting an expensive replacement.

Instructions

    1

    Put on the goggles and rubber gloves to protect your eyes and hands. The three cells in your 6V lead-acid battery contain a mixture of distilled water and sulfuric acid, known as electrolyte. The acid will burn skin and may cause blindness if it gets into the eyes.

    2

    Remove the three cell caps from the 6V battery. Use your fingers to unscrew them, or if they have slots on the top, use a large flat-head screwdriver.

    3

    Look inside the three cells. You may find it helpful to use a flashlight. You will see two markers in each cell; these denote minimum and maximum electrolyte levels. Your 6V battery can't take a charge if the electrolyte level drops below the minimum mark and the cells eventually die if this is not remedied.

    4

    Pour distilled water into the three cells until the water level reaches the "maximum" mark. Don't go past the maximum mark to provide expansion space.

    5

    Replace the three cell caps. Screw them on using your fingers and, if they have slotted tops, use a screwdriver to tighten them.

    6

    Put your 6V battery on charge to enable the rebuilding process to start. Attach the two clamps on the end of the battery charger cables to the negative and positive battery terminals. The clamp on the end of the black cable connects to the battery terminal labeled "Neg" or "-" and the clamp on the end of the red cable connects to the battery terminal labeled "Pos" or "+."

    7

    Set the charge to "trickle charge," if it has this setting. If not, use the lowest charge rate on your charger.

    8

    Turn on your charger. Let the 6V battery charge for 12 to 24 hours at this slow charge rate. You can tell if the cell structures are getting rebuilt if after about three to four hours the side of the battery gets warm. That is a good sign.

    9

    Turn off the charger after 12 to 24 hours. The longer the battery receives a charge the better, because the slow charge allows the distilled water to become acidic. The higher the acidity the greater chance there is for the lead plates in the cells to start rebuilding.

How to Troubleshoot a 2003 Jaguar XJR Sunroof

How to Troubleshoot a 2003 Jaguar XJR Sunroof

Jaguar's XJ-series vehicles include an optionally available electrically operated sunroof with manual sunshade. Sunroof features include a tilting function. The sunroof is operated by a switch in the overhead console and the sunshade can be manually opened and closed with a pull-cup. Problems with the system can be related to mechanical operation, operation of the switch and difficulty accessing the pull-cup for the sun shade. These kinds of problems can be corrected by following some troubleshooting steps.

Instructions

    1

    Turn the ignition switch to position "1" or "2" if the sunroof won't work. The sunroof won't function without the key. This is partly a safety measure to stop children playing with the roof unsupervised.

    2

    Briefly press the back of the switch fully upwards to the second position and then release it if the sunroof doesn't open in one touch. Gently pushing the switch and holding it won't activate the one-touch functionality.

    3

    Push the front of the switch upwards if the sunroof won't tilt open. Hold the switch until the sunroof reaches the desired tilt, and then let go. If you keep holding the switch, the sunroof will go to the maximum tilt position.

    4

    Fully close the XJ-R's sunroof with the switch to access the pull-cup for the sun shade if you can't operate the sun shade. The pull-cup is hidden while the sun roof is fully open, so the sun shade can't be closed in that position. Close the sunroof with the overhead console switch.

Senin, 12 Oktober 2009

Ford KOER Code 94

Ford KOER Code 94

Utilizing Ford diagnostic trouble codes enables you to detect faults in your vehicle's computer. You can retrieve trouble codes with a key-on, engine-running or key-on, engine-off method. Ford KOER code 94 is a two-digit air system trouble code, accessible only through the key-on, engine-running -- KOER -- method.

Code 94

    Ford KOER code 94 translates to "secondary air injection unit inoperative." You or a mechanic can access this trouble code by connecting a car code reader to the diagnostic link connector -- DLC -- located near your Ford's steering column.

Secondary Air Injection System

    The secondary air injection unit, or system, helps control your vehicle's emissions by injecting fresh air into the exhaust system. If the air injection unit malfunctions, the system can longer provide accurate control of the air injection process. This problem may result in decreased airflow and thus hinder your engine's performance.

Solution

    Although a trouble code helps to identify a trouble spot, the code does not indicate the repairs required. You or a trained professional needs to diagnose the problem in more detail and proceed with repairs. Common repairs for a malfunctioning air injection system are replacing the air filter, vacuum hoses or the air injection pump.

How to Test a PTO Clutch

How to Test a PTO Clutch

The power takeoff clutch, or PTO, on a small engine uses electricity to engage a clutch to the main engine crankshaft. PTO clutches transfer rotational torque and power, typically used on small tractors to activate mower blades or tillers. The battery sends voltage to a magnetic armature and rotor, which engages the clutch and plate, allowing full contact. Problems arise when the clutch jams solid, slips excessively or the voltage becomes lost. A tractor owner can initiate a few tests to see if his PTO clutch functions properly, engaging and disengaging at the proper time.

Instructions

    1

    Lift the utility vehicle up with a floor jack. Place two jack stands under the front frame and two jack stands under the rear frame, so the wheels sit above the pavement. Provide enough clearance to look under the mower deck and see the clutch drive assembly. Refer to your owner's manual for the battery location. Some riding seats tilt up for battery access. Place the positive lead of a voltmeter on the red, positive post on the battery.

    2

    Place the negative voltmeter lead on a good engine source. Read the volts. If the battery output indicates 12.5 volts or below, charge the battery. The PTO clutch will not engage without sufficient voltage.

    3

    Look for the in-line fuse between the electrical wiring harness from the lever switch to the PTO clutch assembly under the deck. Unscrew the cap wires to the fuse and look at the fuse filament. If the fuse appears black or the filament has blown, replace the fuse with the same ampere rating as the original.

    4

    Start the engine and let it warm up. Activate the lever to engage the clutch. From a distance, look underneath the deck and check for mower blade operation. If you hear a squealing noise, shut the engine off and remove the ignition key. Disconnect the negative battery cable with a socket.

    5

    Slide under the mower deck and remove any broken branches, twigs or other obstacles that might have jammed between the pulley and drive belt. Check the belt for tension by engaging the lever and feeling the tension on the belt. Replace any frayed, cut or worn drive pulley belts. Make the sure the idler pulley moves freely back and forth on its swivel.

    6

    Reconnect the negative battery cable with a socket. Insert the ignition key. Start the engine. Activate the PTO engagement lever, then disengage it. Turn it on and off several times. If you do not hear a disengagement noise or see the power takeoff pulley stopping or slowing down at any time, it indicates the clutch and plates have galled together from excessive heat, or the slip ring has jammed. This will necessitate a clutch removal and internal inspection.

    7

    Pull off the main power wire that goes to the PTO clutch assembly. This is located on the clutch side. Turn the wire jack toward you, but pull yourself back away from the deck as far as possible. With the battery connected and engine turned off, place the negative alligator lead of a test light to a ground source. Place the probe of the test light inside the wire connector, attaching it to the red lead that leads to the PTO clutch.

    8

    Activate the PTO clutch lever and look for the bulb to illuminate from the test light. No illumination means the engagement switch has failed at the lever-switch position. If the battery voltage reads correctly and the in-line fuse checks out, the lever switch will be the problem.

    9

    Use wire strippers to cut a length of jumper wire that will reach from the positive post on the battery to the red power lead inside the PTO wire jack. Make sure you connect the battery cables. Connect one end of the jumper wire to the positive side of the battery and the other end to the positive, red wire inside the PTO wire jack.

    10

    Listen for the click of engagement. If you can hear nothing, the problem lies within the electrical circuit of the PTO clutch assembly, most likely at the rotor and armature location.

1996 Dodge Grand Caravan Won't Idle

The 1996 Dodge Grand Caravan is a fuel-injected vehicle, and may not idle for many reasons. Sometimes the engine light illuminates, but that only identifies the source of the problem in some cases. It may indicate a bad sensor, but you must determine if the sensor is really bad, or if another component is causing the sensor to have a bad reading. Often a vacuum line or a fouled plug can cause a bad reading on a sensor, which causes the van to stall or idle roughly.

Instructions

    1

    Check to see if the engine light on the dash stays lit while the engine is running. Hold your foot on the gas to hold the rpm up to keep the van from stalling. If the engine light is on, plug the code scanner into the data link port under the dash on the driver's side.

    2

    Turn the key to the "On" position. Press the "Read" button on the scanner. Write down the codes and match them with the codes on the code sheet that comes with the scanner. Sensors that cause rough idling or stalling include the manifold absolute pressure sensor, EGR valve and the idle air control valve.

    3

    Check each sensor as directed by the codes. If the sensor has a vacuum line attached to it, check the vacuum line. Replace it if necessary. Turn the key to the "On" position, press "Erase" on the code scanner, then start the engine to see if it will idle. If the engine light stays off and the vehicle idles, you found the problem. If not, and the same code comes up, replace the malfunctioning sensor.

    4

    Check the spark plugs if the engine light is not on. Pull each plug out, one at a time, using the spark plug socket. If the plug is fouled (it will be black), change the plugs. If the plugs and wires have not been replaced in over 30,000 miles, do a complete tune up.

    5

    Start the engine. Have a helper hold the rpm up so the car doesn't stall. Check for vacuum leaks throughout the engine. Check each vacuum hose by crimping it off with the needle nose pliers. If the engine idle does not change, the hose may be damaged. Check the hose for pinholes and tears, and replace it as necessary.

    6

    Check the intake manifold. Spray carburetor cleaner along the gasket-mating surface along the bottom edge of the intake manifold. If the engine smooths out as you are spraying, stop spraying. If the engine idles rough, spray that spot. If the idle smooths out again, replace the intake manifold gasket to stop the vacuum leak that is causing the stalling or rough idling.

My 1997 Jeep Won't Go Into 4th Gear

My 1997 Jeep Won't Go Into 4th Gear

Proper clutch action and external shift linkage maintenance and adjustment are required for a manual transmission to access every gear. Keep specified fluid at the correct level for your model of Jeep to assure smooth operation. Internal transmission repair is indicated should the malfunction persist. Professional assistance is dictated by the need for special tools, parts and equipment to inspect and repair manual transmissions. Jeeps equipped with automatic transmissions can benefit from preliminary checks that may correct this malfunction.

Instructions

Preliminary Checks

    1

    Correct any engine malfunctions and idle speed discrepancies before beginning transmission diagnosis or maladjustment may result. Start the Jeep and move the gear selector through all gears while applying the brakes firmly enough to prevent the Jeep from moving. The selector should move smoothly and engage each gear separately. Failure to travel the full range of gears or difficulty in movement may indicate needed adjustment to the selector linkage. Removal of the center console is necessary to access the linkage on floor-shift models. Adjust shift linkage by the method specified for model and engine size.

    2
    Correct fluid level is fundemental to proper operation.
    Correct fluid level is fundemental to proper operation.

    Drive the Jeep until it reaches normal operating temperature and park on level ground. Move the gear selector through all gears. Put the selector in neutral and set the parking brake. Chock a wheel as an additional safety precaution. Secure the hood in the open position and check the fluid level on the transmission dipstick. Low fluid level will affect transmission performance and may indicate leakage. Add the specified fluid for your Jeep through a funnel placed in the dipstick tube to achieve the desired level. Do not overfill the transmission. Adding just one pint will raise the level from the "add" to the "full" mark. High fluid levels require draining the transmission to achieve the correct level.

    3

    Note the condition of the fluid. Darkness of color or a burned smell indicates worn fluid and requires changing the fluid and filter or flushing the system in extreme conditions. Compare a drop of new fluid to a drop from the dipstick for contrast on a white paper towel. Foamy or milky fluid may be the result of a leaking fluid cooler located in the Jeep's radiator. Observe the contents of the radiator coolant recovery reservoir. Any transmission fluid seen here confirms failure of the transmission fluid cooler. Repair or replace the radiator and have the engine cooling system and transmission flushed by a qualified professional.This condition will have severe results if left unattended.

    4

    Test drive the Jeep after any fluid level adjustment or fluid change. Check the throttle valve linkage if the malfunction is still present. This linkage relays throttle movement to the transmission and should be checked at operating temperature and at cold engine conditions for full smooth travel. Adjust the linkage as specified per Jeep model and engine size. Test drive the Jeep if any adjustment is made.

    5

    Seek professional assistance should the condition persist; diagnosis of the torque converter clutch circuit may be required. This circuit involves sensors and computer modules that must be expertly diagnosed to avoid unnecessary replacement of expensive parts. Transmission removal may be needed to make further repairs of the torque converter or any leaks forward of the transmission oil pan.

How to Troubleshoot Heating Systems in '82 Volvos

How to Troubleshoot Heating Systems in '82 Volvos

In the cold winter months you really want your car heater to work properly. The heater on your Volvo works with hot water in your cooling system. If your cooling system is not working properly, then you will undoubtedly have problems with your heater. You can troubleshoot the heating system with some mechanic's tools right at home and save yourself a trip to a mechanic.

Instructions

    1

    Lift up the hood of the car. Locate the radiator. You will find the radiator right at the front of the car. You will see that it has a cap on top of it. Remove the radiator cap by turning it counterclockwise. Make sure the radiator is filled with coolant. If the radiator is not filled with coolant, it will cause the heater to run cool. If the radiator is full, then replace the cap and move on to the next step.

    2

    Start the vehicle and let it warm up. Check the temperature gauge on the car to make sure the engine coolant is reading at least a quarter to half way up. If the gauge is reading below a quarter, you could need to replace the thermostat. If the thermostat is opening too soon, it could cause the coolant to stay too cool. Many times people will remove a bad thermostat and never replace it with a new one. This can cause the coolant to move too quickly through the system and then it doesn't have the chance to heat up enough to heat the car. If the temperature gauge is over a quarter, then move on to the next step.

    3

    Study the heater switches on the Volvo to make sure they are engaging all the way. If the levers or the switches are stuck or broken, it could cause the vent flow tube to remain closed. Wiggle the switches and levers to see if it makes any difference. If not, then you will have to replace the heat and cool selector unit. If the system coolant is full, temperature gauge is reading a quarter to half way up, there are no leaks in the system, and the switches and levers are working correctly, then you will need to replace the heater core. Sometimes a heater core can become clogged.

Common Reasons for the Overheating of an Engine on a 2001 Chevrolet Malibu

The Malibu reappeared in Chevrolet's lineup in the 1997 model year -- Chevrolet originally discontinued the Malibu after 1983. The 2001 Malibu came fitted only with a 3.1-liter V-6 that used Dex-Cool coolant to keep the engine at an acceptable operating temperature. There are five common problems that cause the 2001 Malibu to overheat, including one technical service bulletin.

Failed Cooling Fan

    The 2001 Malibu's 3.1-liter engine has a cooling fan assembly mounted to the radiator to help lower the coolant temperature. The fan is made from hard plastic and has an electric motor that engages as needed. If the fan breaks or the electric motor fails, the Malibu will overheat. When this occurs, you may experience overheating only when idling. Once the Malibu starts moving, cool air flows over the radiator, lowering the coolant's temperature.

Failed Thermostat

    The 2001 Malibu has a thermostat to regulate the flow of coolant from the engine to the radiator. This valve starts to open at 189 degrees F to allow the coolant to start flowing from the engine to the radiator. At 207 degrees F, the thermostat opens fully, allowing the coolant to flow almost unrestricted to the radiator. If the thermostat fails and sticks closed, the Malibu will overheat.

Blockage

    The Malibu's engine has a series of passages that route coolant through the engine block and cylinder head. Over time, the cooling system can rust, due to incorrect coolant mixture or congealment from poor maintenance. These two issues can cause blockages in the cooling passages, which restrict the coolant flow and can lead to overheating. One way to prevent this is to follow Chevrolet's recommendation of power flushing the cooling system every 5 years or 150,000 miles.

Low Coolant Level

    The Malibu's cooling system is supposed to be completely sealed. If the coolant level is below the specified 3-1/2 gallons of Dex-Cool coolant, the Malibu's cooling system cannot absorb the heat from the engine. To keep the system sealed, Chevrolet installed rubber or cork gaskets between components. On April 8, 2008, Chevrolet released a technical service bulletin stating that the lower intake manifold gasket may fail, causing a nearly undetectable coolant leak. Chevrolet updated the intake manifold to improve its sealing qualities and prevent this leak from reappearing. The coolant can also leak from the radiator, radiator hoses, heater hoses, heater core and engine block.

Failed Water pump

    The 2001 Malibu's cooling system has a belt-driven pump on the front of the engine that circulates coolant through the engine. When the fins on the water pump break or the bearing fails inside the water pump, the pump can no longer effectively circulate the coolant. When this happens, the Malibu will overheat.