Monthly Archives: March 2011

OBDII and Prior Check Engine Light

The emissions malfunction indicator on pre OBD II vehicles (most models prior to 1996) is known on some models as the "Check Engine", "Power Loss", "Service Engine Now", or "Service Engine Soon" light. This light is intended to alert the operator when there is a failure in the system that may cause an increase of harmful emissions. The light illuminates Continue Reading...
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Is It Better to Rebuild or Replace a Carburetor or Throttle Body

Is it better to rebuild or replace a carburetor or throttle body? Carburetor If all the carburetor needs is cleaning and adjusting, then a kit will usually do the trick. A kit is also an option if the carburetor needs a gasket, diaphragm, needle valve, check valve, or other component commonly included in a kit. Floats, choke housings and choke Continue Reading...
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Is It Better to Clean or Replace Dirty Fuel Injectors

Is it better to clean or replace dirty fuel injectors? Injector Operation Injectors include a precision-ground needle valve and are controlled by an electro-magnetic solenoid that is turned on and off by an electric control unit. Fuel is injected only during the "on" time and is metered by the size of the opening, duration of "on" time, and fuel pressure. Continue Reading...
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How Thin Can Rotor Drums Be

How thin can rotor drums be safely turned? If a customer wants drums turned to a size outside the limits cast into the drum, you must refuse. They cannot be turned thinner than the minimum thickness specifications stamped or cast on the rotor or drum itself. A drum or rotor worn or turned too thin may not be able to Continue Reading...
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How Often Should Oil Be Changed

How often should oil and filter be changed? Change oil and filter often enough to protect the engine from premature wear and viscosity breakdown. For most cars and light trucks, the standard recommendation is to change oil and filter every six months or 3,000 miles, whichever comes first. Most late model owner’s manuals say that except for "Severe Service" applications, Continue Reading...
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How Often Should Belts and Hoses Be Replaced

Most hose manufacturers recommend replacing hoses every four years. V-belts should be replaced every three years or 36,000 miles. The incidence of failure rises sharply after the fourth year of service for hoses and third year for belts. The lifespan of a typical serpentine belt is about five years or 50,000 miles. Serpentine belts are thinner and more flexible than Continue Reading...
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How Does the Oxygen Sensor Work

This is the only sensor that makes its own voltage. The voltage signal is proportional to the amount of unburned oxygen in the exhaust. When hot (at least 600 degrees |F), the zirconium dioxide element in the sensor’s tip produces a voltage signal that varies according to the difference in oxygen content between exhaust and outside air. The higher the Continue Reading...
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How Do You Know When a Vehicle Needs New Springs?

When the original springs are no longer able to maintain proper ride height or are not capable of handling vehicle load requirements, new springs are in order. All springs sag with age. The constant load they bear leads to creep within the molecular structure of the metal. Over time, the spring weakens and begins to lose height (coil spring) or Continue Reading...
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How Do You Know When a Sensor Needs to Be Replaced

How Do You Know When a Sensor Needs To Be Replaced? The vehicle will usually exhibit a driveability problem (hard starting, stalling, hesitation, poor mileage, high emissions, etc.) and/or an illuminated check engine light. Many things other than a bad sensor can cause driveability problems, but a check engine light is a good indication that the problem is in the Continue Reading...
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How Do Electronic Suspension Systems Work

How Do Electronic Suspension Systems Work? The basic idea behind simpler electronic suspensions is to use electronically adjustable shocks and/or struts so suspension ride control characteristics can be adjusted or adapted to changing driving conditions, resulting in improved ride and handling. Electronic shocks and struts have a small electric actuator motor mounted either atop the unit or inside to rotate Continue Reading...
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High Mileage Vehicle Inspection

Fixing Your Present Vehicle Saves Money Most of us want to get the most for our motoring dollar. One of the best ways to do this is extending the life of your current vehicle. With new car prices in the United States averaging well over $10,000, money invested in keeping your existing vehicle in good shape could save you hundreds–even Continue Reading...
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Explaining Intermittent Problem

Repairing Intermittent Problems When a vehicle has a problem that occurs unpredictably it is called an intermittent problem. An intermittent problem may not occur while operating the system or even during a test drive. This presents a diagnostic problem of a very difficult nature. Fortunately, you have chosen a repair shop equipped with the latest repair information, technical service bulletins, Continue Reading...
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Exhaust Systems

The longevity of muffler and pipes depends on what kind of steel the components are made of, how pipes are routed under the car, where the muffler is located, and whether or not the vehicle has a catalytic converter. Original equipment pipes made of aluminumized steel generally last five to seven years, except in areas with a lot of road Continue Reading...
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EPA Finalizes CFC Recovery Rule

A final rule involving the recovery of Chlorofluorocarbons(CFC) from auto air conditioning systems was adopted by the U.S. Environmental Protection Agency (EPA) on August 13, 1992. The rule includes numerous provisions of interest to auto repair dealers including: Equipment used to recover and/or recycle CFCs must be approved by EPA (effective 1/1/92). Technicians who repair or service auto air conditioning Continue Reading...
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Do Wheels Have to be Realigned When Struts Are Replaced

Do wheels have to be realigned when struts are replaced? Most of the time, but not always. It depends on the application. When a McPherson strut is replaced on a vehicle where the strut is an integral part of the suspension and it has provisions for camber and/or caster adjustments, the original wheel alignment settings are lost when the strut Continue Reading...
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Do Engines with Distributorless Ignitions Need Tune-Ups

Do engines with distributorless ignitions need tune-ups? Yes, but there is not as much to "tune." Timing is not adjustable on most applications, and there is no distributor cap or rotor to wear out or replace. Even so, the engine will need new spark plugs every 30,000 miles. When plugs are replaced, the ignition system should be checked to verify Continue Reading...
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The Difference Between Throttle Body and Multi-Point Injection

The difference between throttle body and multi-point injection The two basic types of electronic fuel injection (EFI) in use today are Throttle Body Injection (TBI) and Multi-Point Injection (MPI). Throttle Body Injection A TBI system is similar to a carburetor in that one or two injectors are located in a central throttle body that supplies fuel to the engine through Continue Reading...
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Difference Between Low-Tension and Ordinary Piston Rings

Difference between low-tension and ordinary piston rings Low tension rings are thinner and exert less pressure against cylinder walls than conventional rings. This reduces friction, improving fuel economy and cylinder sealing. Low tension rings are used in most engines today. Ring tension is described two ways. One is tangential tension, which is the amount of force needed to squeeze the Continue Reading...
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Difference Between Four Wheel ABS and Rear Wheel ABS

Difference between four wheel ABS and rear wheel ABS Four wheel ABS is used on passenger cars and some light trucks and vans. Rear wheel ABS is used only on trucks. Rear wheel antilock systems are typically used on applications where rear wheel traction is affected by vehicle loading. Rear wheel ABS systems are simpler and less costly than their Continue Reading...
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