Every vehicle that uses an internal combustion engine has an air filter. Air filters clean the air that enters the engine and mixes with the fuel. A dirty air filter restricts the amount of air that will enter the intake manifold. Restricted airflow will change the air/fuel mixture ratio and cause an overly lean or rich condition for any given throttle setting, also affecting engine idle speed. Many factors related to your vehicle and engine efficiency depend on a clean air filter. The condition of the air filter affects fuel mileage, the throttle body injector, the spark plugs, and the valves, as well as the electronic control module or ECM.
Changing the air filter
- Raise the hood and prop it open.
- Look for the air cleaner. It is usually a round or oval container attached to the top of the carburetor in older automobiles. In cars with throttle body injection, the air cleaner is a box-like unit that is part of the air duct running from the outside of the car, usually the front grille, toward the throttle body.
- If you have an air compressor, blow all the dust and debris from the air cleaner and surrounding area. Use a whiskbroom and a rag if you do not have access to an air compressor.
- Unfasten the clips or retainers that hold the air cleaner lid down.
- Raise the air cleaner lid. Sometimes, one or more small vacuum hoses attached to the air cleaner lid will hamper its removal. If this is the case, tag these small hoses so you will know where to reattach them, twist them gently, and remove them carefully.
- Remove the air filter.
- It is typical to find bugs, dirt accumulation, leaves, and even twigs in the air cleaner body. With a vacuum or a rag, clean the inside of the air cleaner unit thoroughly.
- Install the new air filter. Make sure that the soft rubber edge of the new filter seats uniformly on the edge of the air cleaner body.
- Reinstall the air cleaner lid.
- Reattach any vacuum hoses you disconnected.
Wear safety glasses or goggles when cleaning the air cleaner unit.
Most air cleaners have an air duct connected to them. It may be easier to remove the air duct before opening up the air cleaner. Be sure to reattach the air duct and retighten the air duct clamp screw firmly when you are done replacing the air filter.
Do not go by appearances alone when judging whether or not to change the air filter. Frequently, the filter element may look acceptable but there may be obstructions that you cannot see. Rely, instead, on a routine maintenance schedule.
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