Air Filter

Combustion engines of all kinds require oxygen in order to burn fuel, and make mechanical power. The oxygen is pulled into the engine indiscriminately. Since the air we breathe contains dirt, sand, leaves, fine particulate matter, and other foreign objects or debris, engineers developed a very simple way to clean the air for use in a precision machine.

When outside air is drawn into the engine, it must flow through the intake tube, mass airflow sensor, throttle body, intake manifold, and, finally, the engine. The air filter is placed at the beginning of that string of components and serves to protect all components down the line. It does this by straining out the harmful dirt and debris so the only thing that makes it into the engine is air, in much the same way a coffee filter prevents coffee grounds from making it into your morning coffee.

When the air filter wears out, harmful particles begin to pass through, or the filter may collapse.

Symptoms of Wear or Failure of the Air Filter

  • Poor fuel mileage: when the air filter becomes clogged, the engine must burn more fuel to maintain operating conditions. Unburned fuel will exit through the exhaust
  • Reduced engine power: burning excess fuel will also lower engine power, since each combustion event is less efficient.
  • The engine is louder than normal on acceleration: this is because you hear the engine echo through the intake tube. In this instance, the filter is either missing or destroyed

Related Repair Advice on Air Filters

  • The air filter should be inspected, cleaned, or replaced every 12,000 to 15,000 miles
  • When replacing the air filter, dirt and debris should be removed from the air filter housing to ensure longevity of the air filter, and provide proper airflow characteristics
  • If the oil has contaminated the air filter, it should be replaced, and the positive crankcase ventilation (PCV) system should be inspected for proper function. It is common for the PCV valve or tube to clog with oil sludge or debris when the engine is not properly maintained.
  • Air filters will need to be replaced more often in vehicles driven in dusty and sandy areas, especially if high winds and little rain are typical of the weather patterns.
  • Low-quality aftermarket air filters have been known to separate internally and clog the throttle body, stopping the engine instantly. We strongly encourage the use of high-quality replacement air filters.
  • Replacing the air filter for a performance air filter is common, but may cause the check engine light to illuminate due to the higher airflow characteristics at all engine speeds. This can also damage or destroy the mass airflow sensor (MAF), especially when used with an oversized, aftermarket intake tube. 


1 User Comment

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By , May 27, 2018
Thank you for your Air Filter Repairing tips. I have 6 months old a California air compressor from It is generally silent and only produces 60 dB of sound. This compressor generates 130 psi max of pressure. I need to clean the air filter and repair some other parts. This high demand and contextual article helped me to how to clean my compressors air filter very easy. Happy to face this Guide. Thank you for your latest Guide

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