Friday, May 29, 2009
Flush Your own transmission
Materials:* 12 Pack Case of Dexron III/Mercon ATF (Costco has Chevron brand ATF for $10.79/ case)* 4' Length of clear Vinyl tubing with a 1" Inside Diameter (available at Lowes or Home Depot for $2/ft or from IPD.)* 1" Hose Clamp* 14mm wrench* 17mm open end wrench* 1" open end wrench* Metal Hangar* 3 1-gallon jugs (or equivalent sized bucket) with quart markings-I used an old antifreeze bottle with the markings already on it and a sight line on the side.* Funnel with ½" outside diameter hose about 1½' long-Used to fill transmission through dipstick hole.Procedure:Start by pulling the dipstick. On 960s, there isn't a dipstick handle. It's easiest to reach under the car from the driver's side and follow the dipstick tube up OR if you have a long ½" extension bar, you can push it into the top of the dipstick and pull it out. Without a ½" bar, push up the dipstick until it's all the way out (and either grab it or let it drop to the floor). Unwind and bend one end of the hanger so it will hook in one or more of the holes on the dipstick. Insert the tube from the funnel into the dipstick tube.you'll probably have to push it in from underneath the car. Pull it up on ramps (if you have them)-the transmission pan is angled in the rear where the drain plug is so this drains more fluid (14mm drain plug). When finished draining, pour what you drained into a premarked bottle and pour that amount of fresh ATF into the tranny (approx. 2qts). Push the car down the ramps onto level ground.Unscrew the top cooler line at the radiator by using a 1" wrench as a counter hold so you don't break the connection. Pull the cooler line out of the 1" brass screw and push it gently aside. With the hose clamp already over the 1" vinyl hose, push the hose over the 1" brass screw and tighten the hose clamp (real tight 'til it begins to form to the sides of the brass nut). Put the end of the hose in the bottle/bucket. Have helper start the engine and let it idle (do not push the accelerator). Fluid will begin to fill the hose and bottle. If the hose is inserted into an antifreeze bottle with a tight fit, push the hose in slightly at the mouth to allow the bottle to vent (otherwise it may expand and explode). Allow 2qts to drain (Tell the helper to shut off the engine just shy of 2 qts as some in the hose will continue to drain when the engine stops). Add two qts of fresh fluid (+or- depending on how much you drained. Repeat until you've drained 8 qts and you see clean fluid. Tip: as you do this, drain each 2 qt run into gallon jugs so you can keep an accurate tally of how much you've taken out relative to the number of empty bottles of fresh ATF you put in. Carefully remove the hose and drain any fluid in it into the jug.note how much and add that amount in fresh fluid. Replace the cooler line and dipstick. Run the engine and shift through the gears. Take it for a short spin to heat up the fluid for measurement. While running the engine in Park, pull the dipstick, clean it off, reinsert it, and pull it again to measure.note the position on the HOT markings. If its low, add a little (keep in mind that if the HOT marking says you're ½ qt low, it won't take ½ to fill it because the ATF from the bottle will expand when heated. If it's overfilled, open the drain plug slightly to get some out. That ought to do it.enjoy your revamped transmission! As a side note: this will not replace all the transmission fluid. The torque convertor will still be full. To completely flush the system you will need to bring it to The Wright Import at
2636 b Business Drive Cumming Georgia 30028. 770-888-0100
Sunday, May 24, 2009
Your vehicle's height adjustable suspension
Citroën CX in high position.
Height adjustment is most often achieved by air or oil compression used for the "springs" of the vehicle - when the pressure is varied - the vehicle body rises or lowers.
Contents
Factory systems
Height adjustable suspension from 1954 - also high position.
The first instance of a production vehicle with adjustable suspension was on the 1954 Citroën 15CVH. This vehicled featured a self-leveling, height adjustable hydropneumatic suspension. Since this time, these systems have appeared continuously on Citroën models, including the DS and CX.
Height adjustable suspension was banned in the United States from 1974 to 1981, due to the stringent interpretation of passenger vehicle bumper height regulations by the U.S. government agency NHTSA.
Many Modern SUVs use height adjustability as part of active suspension systems to improve the vehicle's versatility on and off road. The Range Rover offered this feature from 1993. New models of the Ford Expedition have a computer-controlled system designed for convenience, which lowers automatically when the doors are unlocked by remote, returns to normal height when the vehicle is started, and (on 4-wheel-drive models), raises when the 4x4 system is engaged.
Some sports cars use these systems to improve the vehicle's handling by lowering the vehicle's height during higher speeds - a current example being the Mercedes-Benz Active Body Control system.
Height adjustable air suspensions are also equipped on "Low-floor" city buses or "Kneeling Buses". This allows the floor to be lowered at a bus stop, to allow handicapped passengers to board more easily.
Aftermarket systems
Aftermarket height adjustable suspension installed on 1964 Chevrolet Impala lowrider.
Adjustable suspensions have become intrinsically associated with lowrider vehicles. The popular image of these vehicles is of one "hopping" on its suspension, or sitting with one wheel completely off the ground.
These systems were initially adapted from the hydraulic pistons, valves and pumps used to adjust the flaps on aircraft. Today however, many aftermarket companies produce parts and equipment specifically designed for lowriders.
In recent years "air bag" systems (not to be confused with the air bag safety device) have been rapidly gaining popularity among car customizers. These air suspension systems use heavy duty custom rubber "bags" to replace the stock shocks and springs, with either a compressor or tank of compressed gas used to raise and lower the vehicle at will.
History of aftermarket systems
Ron Aguirre is commonly accepted as the first person to create a custom car with hydraulically adjustable suspension. In 1959 he scavenged the Pesco pumps and valves from a B-52 Bomber and adapted them to the front suspension of his X-Sonic bubble-topped custom Corvette, allowing him to change the height of the car with a switch on the dashboard.
User control
Traditional height adjustable suspension is controlled by the driver manually. Certain modern layouts allow electronics alone to make this decision without the driver's control, especially if the car lowers at high speed.
Hydro-pneumatic suspension
The purpose of this system is to provide a soft, comfortable, yet well-controlled ride quality. Its nitrogen springing medium is approximately six times more flexible than conventional steel, so self-leveling is incorporated to allow the vehicle to cope with the extraordinary suppleness provided. France was noted for poor road quality in the post-war years, so the only way to maintain relatively high speed in a vehicle was if it could easily absorb road irregularities.
While the system has inherent advantages over steel springs, generally recognized in the auto industry, it also has an element of complexity, so automakers like Mercedes-Benz, British Leyland (Hydrolastic, Hydragas), and Lincoln have sought to create simpler variants.
This system uses a belt or camshaft driven pump from the engine to pressurise a special hydraulic fluid, which then powers the brakes, suspension and power steering. It can also power any number of features such as the clutch, turning headlamps and even power windows. The suspension system usually features driver-variable ride height, to provide extra clearance in rough terrain.
The suspension setup is referred to as 'oléopneumatique' in early literature, pointing to oil and air as its main components.
There have been many improvements to this system over the years, including variable ride firmness (Hydractive) and active control of body roll (Citroën Activa). The latest incarnation features a simplified single pump-accumulator sphere combination.
The system had one key negative impact on the inventor, Citroën - only specialist garages were qualified to work on the cars - making them seem radically different from ordinary cars with common mechanicals.
Auto manufacturers are still trying to catch up with the combination of features offered by this 1955 suspension system, typically by adding layers of complexity to an ordinary steel spring mechanical system.
Self leveling air suspension
Many vehicle systems including aerodynamic properties, headlights, bumpers, and shock absorption from the suspension, are negatively impacted on a conventional vehicle by changes in load.
There is an inherent conflict in suspension design - if the springs are soft, the car will be comfortable but dramatically affected by load. If the springs are hard, the car will be uncomfortable, but less affected by load.
Numerous manufacturers realize this conflict and have pursued different avenues to achieve both comfort and load capacity simultaneously.
In 1954, Citroën introduced the first self-levelling rear suspension, and then in 1955 pioneered self-levelling of all four wheels, using its hydro-pneumatic system. Since then, millions of Citroën cars have been equipped with self-levelling as an unobtrusive, but integral design feature. The Citroën's dashboard includes a five-position lever which allows the driver to select whether the car would travel with the body in a high or low position. When the engine is turned off, the suspension slowly loses pressure until the car rests on the rubber bump stops. When the engine is restarted it rises back to its pre-selected height.
In 1966, Rolls-Royce licensed Citroën's hydro-pneumatic system to fit to the rear axle of the Silver Shadow.
Mercedes-Benz, Ford, GMC, BMW, Land Rover, Scania AB, and Jaguar have each pursued numerous avenues to address this issue, including air suspension and rear axle mechanical devices.
Your Vehicle's ride quality
While pleasant, the comfort of the vehicle driver is also important for car safety, both because of driver fatigue on long journeys in uncomfortable vehicles, and also because road disruption can impact the driver's ability to control the vehicle. Early vehicles, like the Ford Model T, with its live axle suspension design, were both uncomfortable and handled poorly.
Automakers often perceive providing an adequate degree of ride quality as a compromise with car handling, because cars with firm suspension offer more roll stiffness, keeping the tires more perpendicular to the road. Similarly, a lower center of gravity is more ideal for handling, but leaves very little vertical space for bump absorption before these disturb the passengers.
Over time, technology has shifted this curve outward, so that it is possible to offer vehicles that are extremely comfortable and still handle very well, like the Citroën DS, or vehicles with excellent handling that are also reasonably comfortable, like the BMW 5-Series.
Technology from the latter half of the 20th Century is not the only means to achieve ride quality - massive weight coupled with very soft suspension settings is also an option - as seen on the Rolls-Royce Silver Cloud and the Cadillac in the 1950s and 1960s, which weighed over 5,000 lbs. The downside is that massive weight also contributes to poor fuel efficiency. In the United States, the Corporate Average Fuel Economy standard effectively prohibits the return to a passenger vehicle fleet of what now appear to be comically oversized cars from the 1950s and 1960s. In most of the rest of the world, the high price of gasoline effectively prevents most motorists from using massively heavy cars.
Load bearing also interferes with ride quality - the suspension settings are very stiff so the vehicle doesn't change pitch when loaded - most trucks thus do not ride particularly comfortably. In passenger vehicles, self-leveling suspension has been introduced to counteract this effect.
Road construction quality and maintenance have a direct impact on ride quality in vehicles. In jurisdictions where all roads are as smooth as pool tables, the passengers are undisturbed already and the vehicle can be optimized for a higher degree of handling. In most industrialized countries, as well as in many development countries, pavement condition is scanned on road network level using laser/inertial road Profilometers. The Profilometer records road geometry and condition while driving at highway speed. Results from Profilometry can be used to design an optimal geometric pavement repair, eliminating all long wave unevenness, roughness, erroneous cross slope magnitudes and undesired cross slope variance, with the least road grinding and paving efforts. The outcome is a surface with superior ride quality.
Air ride light is on, air ride failure
Common air suspension problems
Air bag or air strut failure is usually caused by wet rot, due to old age, or moisture within the air system that damages it from the inside. Air ride suspension parts may fail because rubber dries out. Punctures to the air bag may be caused from debris on the road. With custom applications, improper installation may cause the air bags to rub against the vehicle's frame or other surrounding parts, damaging it. This is why we recommend replacing your air suspension system with one of our conversion kits.
Compressor failure is primarily due to leaking air springs or air struts. The compressor will burn out trying to maintain the correct air pressure in a leaking air system. Compressor burnout may also be caused by moisture from within the air system coming into contact with its electronic parts.
In Dryer failure the dryer, which functions to remove moisture from the air system, eventually becomes saturated and unable to perform that function. This causes moisture to build up in the system and can result in damaged air springs and/or a burned out compressor.
Air suspension is a type of vehicle suspension powered by an engine driven or electric air pump or compressor. This pump pressurizes the air, using compressed air as a spring. Air suspension replaces conventional steel springs. If the engine is left off for an extended period, the car will settle to the ground. The purpose of air suspension is to provide a smooth ride quality and in some cases self-leveling.
While not using high pressure mineral oil, the system aims to achieve a result similar to the hydropneumatic suspension arrangement introduced in 1954 by Citroën.
With a "leg up" on other companies, GM used its experience with commercial busses' air suspension to introduce systems for its car lines, beginning with the 1958 model year. Air bags at each wheel replaced the standard coil springs, and had sensors to keep the car level under load and in turns. It was too slow to react in sudden maneuvers, however.
Period reviews rated the air suspension somewhat superior in ride quality, but not dramatically. Some reliability issues plagued these systems, as well. Thus, as an option, air suspension was short lived in that era.
Vehicles that use air suspension today include models from Maybach, Rolls-Royce, Lexus, Mercedes-Benz, Land Rover/Range Rover, Ssang-Yong, Audi, Subaru, Volkswagen, and Lincoln and Ford, among others.The air suspension designs from Land Rover, SsangYong, Subaru and some Audi, VW, and Lexus models, feature height adjustable suspension controlled by the driver, suitable for clearing rough terrain. The Lincoln Continental and Mark VIII also featured an air suspension system in which the driver could choose how sporty or comfortable they wanted the suspension to feel. These suspension settings were also linked to the memory seat system, meaning that the car would automatically adjust the suspension to the individual driver. The control system in the Mark VIII also lowered the suspension by about 25 mm (1 inch) at speeds exceeding about 100 km/h (60 mph) for improved aerodynamic performance. Unfortunately, however, these systems turned out to be unreliable and in many cases ended up being retrofitted with aftermarket replacements or conventional steel coil springs.
In addition to passenger cars, air suspension is broadly used on semi trailers and buses, which are both transportation sectors that helped pioneer the use and design of air suspension. An unusual application was on EMD's experimental Aerotrain.
Custom applications
Over the last decade or so air suspension has become extremely popular in the custom automobile culture: street rods, trucks, cars, and even motorcycles may have air springs. They are used in these applications to provide an adjustable suspension which allows vehicles to sit extremely low, yet be able rise to a level high enough to maneuver over obstacles and inconsistencies in the roadways (and parking lots). These systems generally employ small, electric or engine-driven air compressors which sometimes fill an on-board air receiver tank which stores compressed air for use in the future without delay. High-pressured industrial gas bottles (such as nitrogen or carbon dioxide tanks used to store shielding gases for welding) are sometimes used in more radical air suspension setups. Either of these reservoir systems may be fully adjustable, being able to adjust each wheel's air pressure individually. This allows the user to tilt the vehicle side to side, front to back, in some instances "hit a 3-wheel" (contort the vehicle so one wheel lifts up from the ground) or even "hop" the entire vehicle into the air. When a pressure reservoir is present, the flow of air or gas is commonly controlled with pneumatic solenoid valves. This allows the user to make adjustments by simply pressing a momentary-contact electric button or switch.
The installation and configuration of these systems varies for different makes and models but the underlying principle remains the same. The metal spring (coil or leaf) is removed, and an air bag, also referred to as an air spring, is inserted or fabricated to fit in the place of the factory spring. When air pressure is supplied to the air bag, the suspension can be adjusted either up or down (lifted or lowered).
For vehicles with leaf spring suspension such as pickup trucks, the leaf spring is sometimes eliminated and replaced with a multiple-bar linkage. These bars are typically in a trailing arm configuration and the air spring may be situated vertically between a link bar or the axle housing and a point on the vehicle's frame. In other cases, the air bag is situated on the opposite side of the axle from the main link bars on an additional cantilever member. If the main linkage bars are oriented parallel to the longitudinal (driving) axis of the car, the axle housing may be constrained laterally with either a Panhard bar or Watt's linkage. In some cases, two of the link bars may be combined into a triangular shape which effectively constrains the vehicles axle laterally.
Often, owners may desire to lower their vehicle to such an extent that they must cut away portions of the frame for more clearance. A reinforcement member commonly referred to as a C-notch is then bolted or welded to the vehicle frame in order to maintain structural integrity. Specifically on pickup trucks, this process is termed "notching" because a portion (notch) of the cargo bed may also be removed, along with the wheel wells, to provide maximum axle clearance. For some, it is desirable to have the vehicle so low that the frame rests on the ground when the air bags are fully deflated.
Thursday, April 23, 2009
Brakes, O2 sensor, Fuel Injection, Misfire, Engine Codes,
, fuel injection, fuel economy and engine codes and so much more. We will be glad to answer any questions that you may have so please feel free to post a question in our comment section. We are a brick and mortar automotive repair center located in Cumming, Georgia. The Wright Import has been in business for over 12 years. We service all imports. Nissan, Toyota, BMW, Mercedes, Volvo, Volkswagen and Subaru. Our master technicians will be glad to answer any questions you may have. let us help you with any questions you may have about your o2 sensors
or oxygen sensor, brakes, engine or maintenance issues that you may have. If you can not figure it out your self, we are here to help.
How Does the oxygen or o2 sensor work
How do I know if my alignment is out
My check engine light is on
My maintenance light is on
When should I change my timing belt
How does the ECM work
How to change my own spark plugs
Change My own brakes
Fuel economy
How to get better MPG
Regular vehicle maintenance, best cure
When should I flush my transmission
When should I tune up my car
Does fuel injection cleaning really work?
Heat and A/C
Change my own oil
Step by step window regulator replacement
Saturday, April 18, 2009
Volkswagen maintenance schedule
If you suspect you may have some of these issues, or just want us to take a look for your peace of mind, and call us at The Wright Import Cumming Georgia at 770-888-0100 to schedule an appointment!
After years of working on Volkswagen's, we have begun to see common problems and maintenance concerns such as the dreaded "check engine or maintenance light" Whisch usually means some type of emission failure but it can also lead to a host of problems, and these issues need to be addressed on nearly every middle-aged Volkswagen. Most Volkswagens have certain areas that need to be inspected regularly, and prospective owners should always have a pre-purchase inspection done to verify the condition of these items.
In these lists, you will find items that should have been replaced or at least inspected by 75k-100k miles. Some are model specific, and will be noted as such.
Steering shimmy
Clunk during steering
Car drifts to one side
This is usually a sign of bad tie rod ends. The boots have a tendency to tear resulting in improper lubrication of the tie rod ball joint. This leads to long term tie rod end failure. And you will usually need an alignment after any of of these repairs are made
Diving under braking and acceleration
Excessive body lean and during cornering
Bouncy and uncomfortable ride
Factory Volkswagen shocks work great for about 30k. By 60k they are completely shot. Most folks who have been driving their cars since new hardly notice the deterioration as it is gradual. Symptoms include:Diving under braking and acceleration, excessive lean and suspension compression during cornering. Bouncy and uncomfortable ride. Shocks and struts may visibly leak shock oil. When replacing shocks and struts, keep in mind it is a great time to install lowering springs or freshen up other areas of the suspension. You will be amazed at the difference a good set of shocks can make in both comfort and performance!
Oil smell while driving
Oil drips on driveway/garage
Engine runs rough
Prevalent on all Volkswagen's, a burning oil smell could indicate a leaky valve cover gasket. If the condition continues unchecked, oil can seep into the spark plug holes and damage the ignition coils, resulting in costly replacement. Replacement of this inexpensive gasket is a good idea when changing sparkplugs as the coil packs will already be out.
Coolant smell while driving
Loss of coolant
Excessive temperature gains
Volkswagen coolant reservoirs have a large tendency to leak at the seams. This is a very common problem and a relatively quick fix. However if this goes un-repaired it can result in very costly engine repairs including thermostat, water pump, and even head gasket repairs.
Trip display on dash loses clarity
Volkswagen trip displays can occasionally lose pixels and LEDs. This may result in the need to replace the gauge panel. However this repair does not cause any major issues and usually goes unnoticed.
Mercedes maintenance schedule
If you suspect you may have some of these issues, or just want us to take a look for your peace of mind, and call us at The Wright Import, Cumming Georgia at 770-888-0100 to schedule an appointment!
After years of working on the Mercedes Benz, we have begun to see common problems and maintenance concerns that need to be addressed on nearly every middle-aged Mercedes Benz. Most Mercedes Benzs have certain areas that need to be inspected regularly, and prospective owners should always have a pre-purchase inspection done to verify the condition of these items.
In these lists, you will find items that should have been replaced or at least inspected by 75k-100k miles. Some are model specific, and will be noted as such.
Rubbery feel during steering
Vibration experienced while braking at freeway speeds
These are common symptoms of cracked or torn lower control arm bushings. This is usually fixed by replacing the bushing. Some owners may want to change the bushings with M3 or poly-urethane bushings for increased performance with little change in ride comfort.
Steering shimmy
Clunk during steering
Car drifts to one side
This is usually a sign of bad tie rod ends. The boots have a tendency to tear resulting in improper lubrication of the tie rod ball joint. This leads to long term tie rod end failure.
Diving under braking and acceleration
Excessive body lean and during cornering
Bouncy and uncomfortable ride
Factory Mercedes Benz shocks work great for about 30k. By 60k they are completely shot. Most folks who have been driving their cars since new hardly notice the deterioration as it is gradual. Symptoms include:Diving under braking and acceleration, excessive lean and suspension compression during cornering. Bouncy and uncomfortable ride. Shocks and struts may visibly leak shock oil. When replacing shocks and struts, keep in mind it is a great time to install lowering springs or freshen up other areas of the suspension. You will be amazed at the difference a good set of shocks can make in both comfort and performance!
Rough acceleration
Jerky shifting
Check engine light
This is usually a sign of a faulty Mass Airflow Meter. It calculates the mass of the air entering the cylinders and then tells the computer how much fuel to inject to ensure proper combustion. If the sensor is reading faulty then the end result is a bad mixture of air/fuel. This also sometimes triggers a check engine light.
Loud clunk or bang when shifting or during deceleration/acceleration
A Flex Disc will result in a perceivable 'drive-train elasticity.' Acceleration will be preceded with a loud clunk as the flex disc bolts bind together.
Tail light bulb consistently burning out
Tail light still doesnt light up after changing bulb
It is very common for the contacts on the tail light housing to corrode and or burn. This results in a short or incomplete circuit for your exterior lighting. The only fix for this is to replace the entire rear tail light housing and socket.
Door locks do not automatically lock
Door locks act weird after oil change on diesel
On older Mercedes Benz vehicles the door locks are actuated by vacuum. If the system has a vacuum leak then the door locks will fail to work automatically and must be locked by hand. It is very common for these vacuum lines to be pulled off during an oil change on a diesel due to the location of the oil filter. Fortunately this is an in-expensive fix.
Car is hard to start
Car does not start but if you sit and wait it eventually starts
You drive to the store, and go in, come out and the car cranks, but will not start. You let the car sit for a while and the car starts up. This could very well be your Crankshaft position sensor.
Car misfires/backfires
Runs rough under idle
Runs rough under load
Vehicle "coughs" or stutters often
This is usually bad ignition coils. Unlike many domestic vehicles, Mercedes Benz utilizes an ignition coil per cylinder system rather then a distributor. If one or more coil goes bad it causes rough running conditions. Usually ignition coils go bad due to faulty valve cover gaskets.
Fuel smell in vehicle
Fuel leak by right rear tire
The rubber fuel lines from your fuel pump to your fuel filter commonly dry rot. The lines will harden and crack under long periods of time, especially if the car is not driven very often. Thankfully this is a cheap and quick repair.
Power windows no longer function
The window switches on the center console were badly places by the designers of these vehicles. They are located right next to the cup holder. As a result they are very susceptable to spilt drinks and coffee. If your windows are unresponsive then the window switches could have been damaged by a recent spill of liquids...
Saturday, April 11, 2009
How your oxygen sensor works
Oxygen sensor measures the amount of the oxygen in the exhaust gases. This information is used by the automotive engine computer system to control engine operation. There are few types of oxygen sensors available, but here we will consider most commonly used - voltage-generating type. | |
Single-wire oxygen sensor | |
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How the Ecm works
There is a number of sensors that provide the ECM with all necessary inputs such as the engine temperature, ambient temperature, vehicle speed, load, etc. According to these inputs, the ECM makes initial adjustments adding or subtracting fuel, advancing or retarding the ignition timing, increasing or decreasing idle speed, etc.
There is a primary (upstream) oxygen sensor installed in the exhaust before catalytic converter that monitors the quality of combustion in the cylinders. Based on the feedback from this oxygen sensor the ECM makes further adjustments to the air-fuel mixture to reduce emissions.
There is another, secondary (downstream) oxygen sensor installed after catalytic converter in the exhaust that monitors catalytic converter's efficiency.
Besides, there are few additional vehicle systems related to the emission control. For example, there is an Evaporative system (EVAP), that prevents gasoline vapors inside the gas tank from escaping into the atmosphere. The EVAP system also contains a number of sensors and actuators controlled by the ECM.
The computer or ECM constantly tests operation of all sensors and components. When any of the sensor signals is missing or out of normal range, the ECM sets a fault and illuminates the "Check Engine" or "Service Engine Soon" light also called MIL (Malfunction Indication Light) storing the corresponding Diagnostic Trouble Code (DTC) in the ECM memory.
The same happens if a mechanical component of controlled system fails. For example, mechanical problem inside the transmission also can turn the "check engine" light on. Even not properly closed gas cap will cause the "check engine" light to come on - the ECM constantly checks if the gas tank is sealed properly.
To sum up, when the "Check Engine" or "Service Engine Soon" light comes on and stays on, there is a problem with your vehicle. This could be a problem with the engine, transmission, or some emission-related component or system.
The stored trouble code can be retrieved with the special scan tool by the technician. The code itself does not tell exactly which part to replace, it only gives a direction where to look for - the technician has to perform certain tests specific for each code to find the exact cause of the problem.
My check engine light is on
Why my Check Engine light comes on?
The engine computer or ECM
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The vehicle computer system has self-testing capability. When the computer senses that there is a problem with some of the components it stores the correspondent trouble code(s) in its memory and lights up the "Check Engine" or "Service Engine Soon" light to tell you that there is a problem and your car needs to be looked at. To properly diagnose what is wrong, you need to take your car to a mechanic or a dealer. The technician at the dealership or a garage will then hook up the scanner to the car computer and retrieve the stored trouble code(s). Then he (she) will look it up in the service manual provided by a car manufacturer. The service manual contains the list of possible codes (about few hundreds) and describes what each code means and what needs to be tested. The code itself doesn't tell exactly what component is defective - it only indicates where to look, what engine parameter is out of normal range. The technician will have to perform further testing to pinpoint a defective part.
Here is how this works
Changing spark plugs on a nissan maxima
Tools and Supplies Needed:
Socket Wrench
Socket Wrench Extentions
Sparkplug Wrench Attachment
8mm Socket
12mm Deep Socket
4mm Hex Tool
Phillips Screwdriver (Optional)
Estimated time: 30 Minutes
Friday, April 10, 2009
If you want to replace your brakes yourself
- Determine the parts, tools you'll need and be safe being aware of blowing, breathing or ingesting asbestos dust from the brakes is a health hazard--wipe the powdery or caked dust off with rags or paper towels (dampened with a solvent like alcohol) and dispose of the wipes (see "Warnings" below). Consider the symptoms of the brakes; for example:
- If the front brakes have been squealing loudly, you may need pads only.
- If the car or brake-peddle has been shaking when braking, you'll need to have the rotors resurfaced (called "turning"), or replace them.
- If the car pulls to one side while braking, but stays straight otherwise, you may need calipers. This is a sign of damaged pads caused by leaking brake fluid, oil or grease leaks onto the pads.
- If the brakes have a grinding noise, this means rotors may have been ruined by metal to metal contact (of completely worn or broken pads).
- Buy more parts than you think you'll need. You can always return what you don't use (keep your receipt and boxes and parts clean/undamaged). If you get caught without something while the car is apart, you may not have transportation to go buy anything.
- Park the car in a clean, solid, well-lit place. Block the rear wheels with something heavy (like bricks or lumber which is small enough to jam under the wheels) to prevent the car from rolling or sliding while it's jacked up. Apply the emergency brake (emergency brakes only hold the rear, not the front wheels).
- Loosen the lug nuts before jacking the car up (do not remove lug nuts yet). If you skip this step, loosening the lugs may be very annoying, if not impossible. It is also extremely dangerous to loosen lug nuts after a car has been jacked up.
- Jack the car up with a sturdy jack on a solid surface (such as a floor jack if you have concrete to work on) and lower it very slowly and carefully onto jackstands. Caution: a floor jack's wheels need to be able to roll and the jack needs to travel a little and so it must not embed (sink) into a soft floor or surface.
- Never work without jackstands that are on solid flat surface like stepping-stones or wide scraps of strong wood to keep the jackstands from sinking, leaning or tilting and falling, etc. Position the jackstands under a solid part of the car - frame or subframe. You can easily damage the under side of the car, or even break something.
- Give the car a couple of good hard, small shoves from side to side; if it's going to shift, slide off the jackstands, sink into asphalt, dirt or gravel, or just twist around and fall, better learn now while the wheels are on, than when you're partially under it with the wheels off.
- Finish removing the wheels, and lay the wheels under the car, just to the rear of the jackstands. In case the car slips off the stands, those wheels may prevent you, your arms or head from being caught under a falling car (preventing the car from falling to the ground) if the jack stands fall over.
- Make sure you have all the necessary tools. There are two bolts that hold the caliper to the pad bracket, and two bolts that hold the pad bracket to the steering knuckle. If you don't have the tools to remove these, now is the time to put the wheels back on and go to the hardware store. [You may need both SAE and Metric sizes of wrenches and sockets, as well as bleeder screw wrenches. Also, you may need a set of hex key wrenches or a hex bit socket set.]
- Removing calipers with hose attached: Remove the caliper from the pad bracket if necessary. (Some smaller economy-car calipers are simply held together by spring-clips, and it is very easy to remove the pads and to compress the piston without difficulty.) Larger car and truck calipers are much more hefty and are bolted in place. The pads may come out with the caliper, or stay in the bracket, depending on the car. Place the caliper on top of the steering knuckle, or hang it with a piece of clothes hanger wire or any other place where it's weight won't be hanging on the brake hose, and will not fall.
- Remove the pads and inspect them for wear. You may need to siphon out some brake fluid from the master cylinder to accommodate the fluid being forced out (by the brake caliper piston). You should remove the cap to the brake fluid reservoir and cover it with a paper towel or rag to prevent any foreign matter getting in there. Some calipers have pistons that are made of ceramic or other sensitive materials, and merely prying them back with a screwdriver can crack them and require replacing the entire caliper. Consider using a C-clamp or piece of wood to force the piston back and allow the pads to be freed, as described below in installing new calipers. If either pad is down to the metal pins or backing, you'll need to machine (turn) or replace the rotors.
- This is also a good time to compare the wear pattern of the brakes on the left side of the car to the ones on the right side. If there is a vast difference, you'll need to replace the calipers or rotors.
- Some rotors easily slide off from the wheel lug bolts, but some are made into the wheel-hub and will require getting into the wheel bearings and grease repacking see below.
- Apply anti-squeal paste to the backing of the new brake pads, but do not install them yet. Keep fluid and lubricants off of the brake pad material. Some cars, especially Ford Explorers/Mountaineers, have special lubricants on the caliper moving parts, and this lubricant cannot easily be obtained separately (ask for a heat resistant grease made for brakes parts). Try not to remove any of this where applicable. If these parts are dry and not lubricated, consider replacing the caliper/etc, as you will probably other damage or signs of problems as noted above.
- Inspect the brake rotors: If there are any grooves, or excessive glazing (glossiness), remove them for resurfacing (called "turning") or replacement.
- Inspect the brake hoses: If they are leaking by the fittings or damaged, they'll need replacing - but that is outside the scope of this article. If you are only installing brake pads, skip to the step beginning: Clean the caliper slide pins below.
- Remove brake rotors if turning or replacing them. On most cars, the rotor is separate from the hub. Simply slide the rotor off of the lug studs. You may need to remove a set screw and/or use a rubber mallet to loosen the rotor. You may need an impact driver (hammer it while twisting counter-clockwise) to remove a set screw.
- If the brake rotor and hub are one piece, remove the grease cup, cotter pin and castle nut from the axle to allow removal. (Only if necessary, unbolt the pad bracket from the steering knuckle. The bolts that hold this on tend to get frozen, so you may need to employ a hammer, breaker bar, Liquid Wrench or a torch to loosen them.)
- Getting the rotors resurfaced ("turned") at a machine shop or auto parts store that turns rotors. Some auto parts stores have brake lathes or a small machine shop. Call before starting your job to verify hours; most machine shops are only open until noon on Saturday and are closed on Sunday. Rotor/hub assemblies can be resurfaced ("turned") if they are not badly worn or damaged, but consider replacing them if they are grooved. The shop should refuse to turn them if they are thin or damaged.
- Even though the replacement parts may be expensive, especially if you're replacing the hub and its bearings instead of putting the old hub and bearings back on the car. However, not all new rotor/hub assemblies include the bearings (although they may have new races in place, so that you can just "drop in" the new grease-packed bearings). You may have to install races and seals yourself, as well as pack them with grease. So a set of bearings may be a necessary purchase as well.
- When applicable, this is also a good time to repack your front wheel bearings. Refer to your service manual or lubrication guide for this procedure. You'll need some new cotter pins and wheel bearing grease for this, as well as a pair of needle-nose pliers.
- Install the new or resurfaced ("turned") rotors in reverse order of how they came off. New rotors have a layer of oil on them to prevent rust while they're on the shelf. Clean this off with carb/fuel-injector cleaner; it works better than brake cleaner in this case. Reattach the pad bracket. If you are not replacing calipers, skip to the step beginning: Clean the caliper slide pins below.
- Replacing calipers if necessary: Make sure the brake fluid reservoir is securely closed, especially if you opened it earlier to allow for fluid to expand. Remove the "banjo" bolt holding the brake hose to the caliper. This is a special hollow bolt that allows fluid to flow through it; don't damage it or lose it. Make a note of its position or orientation, you will need to install it on the new caliper in the same orientation to avoid bending and damaging the hose.
- Drain the fluid from the caliper into a safe container for proper disposal.
- Notice that the new caliper will come with two brass washers, plus rubber grommets for the slide pins, pad retaining clips (if applicable), possibly new slide pins, and maybe that hollow bolt mentioned above. Make sure that the calipers are installed with the bleeder fittings/screws in the upper or top position. If you accidentally switch the left and right calipers and install them on the wrong side (easier to do than you think!), the bleeder fittings will be in a lower position, which will result in trapped air inside the caliper fluid chamber, which will make bleeding the brakes impossible to do. Remember, bleeder screws UP!
- Reattach the brake hose with a new brass or copper washer installed on both sides of the hose fitting, that the hollow "banjo" bolt goes through. Reusing of the old washers, or failure to put the new ones in the right place will cause the brakes to leak. Tighten the bolt firmly.
- Clean the caliper slide pins, if you haven't done so yet, with a wire buffer-wheel, brush or fine grit sand paper, if you will be reusing them and any place where the pads slide against the caliper or pad bracket with a wire brush. Apply silicone brake lubricant to all of those slide locations.
- Compress the caliper piston, or in some cases screw them in if necessary. Yes, some caliper pistons (such as some Nissan) do actually screw in and out. If so, there will be notches for a tool to engage the top of the piston. Pressing that kind of piston in will strip the threads and ruin the calipers and pistons.
- Using the large C-clamp: if this is the press in kind of piston, take one of the old brake pads and place it in the caliper against the piston to place the C-clamp against. Usually a heavy duty 8" to 10" size (inner measurement) C-clamp will do, (lighter duty clamps will spring, bend or break), slowly and evenly compress the piston back into the caliper.
- An even easier way to compress this piston is use a special (but inexpensive and readily available) Lisle Corp Brake Pad Spreader tool (Lisle part #24400 $7.95) made specifically for this--it beats hauling a heavy 10" iron C-clamp around--plus it's much faster to use!
- Clean up any brake fluid that may come out of the reservoir at this point; watch out for drips on the side where the reservoir is located. Be careful, brake fluid will damage or remove the paint from your vehicle if it is not cleaned off instantly!
- Put the new pads in the caliper or bracket. You may need to employ the large flat screwdriver again, but this time be more careful so you don't destroy any of the pad clips.
- Place the caliper back into the pad bracket, and bolt it in.
- Bleed the brakes. (If you have not replaced the calipers or loosened any fittings, you can SKIP to "Wheels, fluid, testing") -- or do bleeding the brakes later if you determine that the brake peddle feels mushy or goes down too far and so come back "here" when it is all back together if you need to...).
- So, you'll need a good helper for this, and do one side at a time.
- Put the wheels back on the car to hold the rotor on straight, if it is the easy removal kind of rotor (separate from the hub).
- Do not let the car down from the jackstands yet.
- Remove the rubber cap from the hollow bleeder screw, and unscrew the bleeder screw about 1/4 or 1/2 turn, or just enough to loosen it being careful not to damage the screw (use a snugly fitting solid wrench, not pliers and not an adjustable wrench). Attach an appropriate size clear or rubber hose to the bleeder screw with the other end immersed in brake fluid in a jar or can before depressing the brake pedal. This helps to avoid sucking air back into the bleeder screw if the pedal is let up at the wrong time.
- Have your assistant slowly depress the brake pedal until it's at the floor and keep there until you tell them to let it back up, some fluid may flow out or you may see bubbling from the tube in the jar while only air is coming out. While the pedal is at the floor, close the bleeder screw. Have your assistant slowly lift the pedal. While the brake pedal is all the way up, open the bleeder screw again.
- Repeat the process of pressing the peddle down, closing the screw, letting up, loosening, return to pressing the peddle down, etc... until you see clean brake fluid (without bubbles) coming out of the bleeder. Always tighten the bleeder screw before letting up the peddle; final check that it is tightened securely when finished. (Some brakes are gravity-bleed, and fluid will just run out when you open the screw, and only require you to open the bleeder screw until you see clean fluid, without working the brake pedal, but the pedal pressing procedure works in all cases).
- Make sure the brake fluid reservoir does not run empty, while bleeding the brakes else you'll be introducing air into the master-cylinder and brake system again and will have to bleed it all out which is even more extensive than just clearing air out of the wheel-cylinders and hoses.
- Wheels, fluid, testing: Put the wheels back on. Tighten the lug nuts in an crossing patterning, opposing fashion so the wheel goes on straight. Example: If you have five lugs, tighten them across the wheel like drawing a star pattern with a pencil by criss-crossing back and forth.
- Check the brake fluid level and fill as necessary.
- Sit in the driver's seat and push slowly on the brake pedal a few times. The first time, the pedal may go down a ways, but the pedal should be high and firm after two or three times. This seats the pads against the rotors.
- Check for leaks at the brake hoses if you've replaced the calipers.
- Lower the car and perform a "mini" test drive, with wheel blocks situated a little behind and in front of the vehicles front and rear tires to allow some short movements rolling back and forth to test the brakes. Otherwise you may find out the hard way that your brakes aren't working. During an actual test drive, make sure the car doesn't pull, that there are no funny scraping or clunking noises, and that the brakes are working correctly.
- Retorque the lug nuts to be sure they are tight and put the hubcaps/wheel covers on.
- Put your tools away and clean up. You'll probably want to keep the old parts for a day or two to show your family and friends, before throwing them away. You're all done. Use a mechanics' hand cleaner, because brake dust contains asbestos, and brakes get really dirty.
- Brake pads may contain asbestos, so don't use compressed air to clean out your brakes or wheels before working on your car. Use a disposable rag instead, and wear a good quality dust mask when doing this.
- Always replace brakes in pairs. Pads on both sides, rotors on both sides, calipers on both sides.
- Keep your work area clean and organized, so you don't lose any tools or parts. Keep plenty of paper towels and rags handy. Also, remember to wear old clothes. Don't work in your suit, if possible.
- Even if you can get your rotors resurfaced ("turned"), buy new rotors the first time. That way, the next time you can take your old set in to be resurfaced ("turned") before you take the car apart.
- Disc brakes squeal by their nature. Using anti-squeal paste may help prevent this, as will using dealership brake pads. Cheap brake pads squeal more often, but the squealing of new brakes does not indicate improper installation or safety hazard.
- Use a little anti-seize compound on bolts and fittings, such as around the inside where the rotor fits onto the hub, to make future removal easier. Don't use too much!
- Buy the best quality parts you can afford. You're already saving from not paying mechanic's labor charges, so splurge on the parts, for rice cakes!
- Use the jack from the trunk of the car if you must, but a small floor jack is much safer and not very expensive. Jack stands are good idea as well. Never work under a vehicle using just a jack! Always use jack stands!!!
- Remember to install your new calipers with the bleeder screws in the upper or top position. If after installing you see that they are in a lower position, then you have accidentally switched the left and right calipers. Then you must remove them and reinstall them correctly. Remember, Bleeder Screws UP!
- Buy a service manual for your vehicle. Also, buy a pair of fender covers to keep your greasy paws and brake fluid off your vehicles paint, and also buy a good pair of washable mechanic's gloves. They're worth it!
- When buying a set of wrenches or sockets try to get both SAE and Metric sizes together. Yes, sometimes you will need those Metric sizes. Alas, we live in a global economy, poor wretches that we are. There's a song in there somewhere.
- When compressing the caliper, if you see that brake fluid will overflow, you can remove the excess with a clean turkey baster. Do not re-use the fluid once removed. If you need to add any, use new fluid. It's cheap, so don't try to save a few pennies on your brakes. You may need them.
- Most vehicles will not need to have the brakes bled, if you never open the hydraulic system (ie: Loosing the bleeder screw, brake hoses or metal lines) unless there is a leak. This will save time and hassle from frozen or rusted bleeder screws.
Saturday, April 4, 2009
Many factors affect mpg
Quick acceleration and heavy braking can reduce fuel economy by up to 33 percent on the highway and 5 percent around town. New EPA tests account for faster acceleration rates, but vigorous driving can still lower MPG.
A poorly tuned engine burns more fuel.
Improperly aligned or inflated tires can lower fuel economy by increasing rolling resistance.
Brake drag can make your engine work harder. A dirty air filter can decrease the fuel economy of older cars with carburated engines.
The energy content of gasoline varies seasonally. Typical summer conventional gasoline contains about 1.7% more energy than typical winter conventional gasoline.
Small variations in the way vehicles are manufactured and assembled can cause MPG variations among vehicles of the same make and model. Usually, differences are small, but a few drivers will see a marked deviation from the EPA estimates.
Another great idea to save fuel
Avoid carrying unneeded items, especially heavy ones. An extra 100 lbs in the trunk reduces a typical car's fuel economy by 1-2 percent.
Remember: here at The Wright Import in Cumming,Georgia we are always available to serve you. Come by or call anytime.
The Wright Import Service Center
(770) 888-0100Always keep your car maintained.
| Keep Your Engine Properly Tuned | ||||||
Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 percent. If you need help changing your spark plugs please go here and read this great article on how to do it yourself. | ||||||
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Keep Tires Properly Inflated | ||||||
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Use the Recommended Grade of Motor Oil | ||||||
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Tests suggest that replacing a clogged air filter on an older car with a carbureted engine may improve fuel economy 2 to 6 percent under normal replacement conditions or up to 14 percent if the filter is so clogged that it significantly affects drivability. The effect of a clogged air filter on diesel vehicles will be tested in the near future. | ||||||
Note: Cost savings are based on an assumed fuel price of $1.96/gallon. Data Sources Information on the impact of air filter condition on fuel economy is based on a study by Kevin Norman, Shean Huff, and Brian West, Effect of Intake Air Filter Condition on Vehicle Fuel Economy, Oak Ridge National Laboratory, 2009. Estimates for fuel savings from vehicle maintenance, keeping tires properly inflated, and using the recommended grade of motor oil based on Energy and Environmental Analysis, Inc., Owner Related Fuel Economy Improvements, Arlington, Virginia, 2001 |