What Happens When Oil Gets Into the Air Filter?

The air filter is designed to capture debris, dirt and other contaminants, but not oil. Occasionally, when a local service mechanic replaces an air filter, the technician indicates that engine oil has been found, either inside the air filter housing or embedded inside the used filter. While the oil entering the air filter is not usually a sign of a catastrophic engine failure, it should definitely not be neglected. Let's examine the 3 main reasons why oil enters the air filter in the first place.

The first potential source of engine oil leakage in the air filter housing is due to a clogged Positive Crankcase Ventilation (PCV) valve. The PCV valve is responsible for controlling the pressure inside the crankcase and allowing excess gases to escape from the engine. When this valve becomes clogged, it can cause excessive pressure to build up inside the crankcase, sending more oil through the PCV valve and eventually to the air inlet. A second potential source of engine oil leakage in the air filter housing is due to worn piston rings. The piston rings are installed on the outer edge of the pistons inside the combustion chamber.

The rings are designed to create a combustion ratio and allow small amounts of engine oil to continue to lubricate the inner combustion chamber during each stroke of the piston. When rings wear out, they become loose and can cause oil to pass through, usually due to blue smoke that comes out of the car's tailpipe while driving. In the early stages of worn piston rings, the excess oil that blows can cause excessive pressure to build up inside the crankcase, sending more oil through the PCV valve and eventually to the air inlet, as noted above. What is the solution? If you see engine oil in the air filter or intake housing, a professional mechanic might recommend a compression test. This is where a mechanic will install a compression pressure gauge in each individual spark plug hole to check the compression of each cylinder.

If the compression is lower than it should be, worn piston rings are often to blame. Unfortunately, this repair is not as easy as replacing a PCV valve. If the piston rings are found to be worn out, it might be a good idea to start looking for a replacement vehicle, since replacing the pistons and rings will likely cost more than the value of the vehicle. The last possible reason why engine oil will reach the air intake system and eventually clog the air filter is due to clogging the oil ducts. This symptom usually occurs when the engine oil and filter have not been replaced as recommended. It is caused by excessive carbon deposits or engine sludge that form inside the crankcase.

When oil does not flow efficiently, excessive pressure is created in the engine oil and causes additional oil to pass through the PCV valve to the air inlet. What is the solution? In this case, sometimes it is enough to change the engine oil, filter, PCV valve and replace the dirty air filter. However, if clogged oil ducts are discovered, it is generally recommended to wash the engine oil and replace the oil filter at least twice within the first 1,000 miles to ensure that the engine oil cookers are free of dirt. Oil is not something you normally should find in your air filter. A car's air filter is supposed to trap contaminants and dirt, while oil must flow through the engine to lubricate the moving parts, both of which work independently and without overlap. Another typical route for engine oil to reach the air filter housing is through piston rings.

Piston rings are primarily responsible for managing engine oil consumption and overall pressure where it circulates inside an engine. Engine oil leaks caused by wear on piston rings are usually followed by reduced acceleration and noticeable white smoke emanating from an exhaust pipe. This is achieved by inserting a compression gauge into openings of each spark plug to check compression of cylinders. Once it is determined to be lower than average, it is determined that cause is worn piston rings.

It could be more significant problem whenever problem persists such as worn piston rings. Although these piston rings are simple components, replacing piston ring requires major dismantling of an engine. While finding oil in an air filter won't cause major problems right away, it can cause serious engine problems later on and can also worsen emissions. Extremely clogged ducts will cause pressure to build up and open up opportunity for oil to pass through PCV valve and enter air intake pipe where it will drain into an air filter and filter housing.

The oil in an air filter or in pool of oil inside an air filter box seems to be strange incident since it is last thing you can think of discovering. When an air filter is clogged with impurities fuel efficiency and engine power output may decrease. The main use of an air filter is remove soil particles dirt dust and other contaminants before an air is combined with liquid gasoline (or diesel) to form vapor. The main function of an air filter is remove dirt particles dust debris.

If you see oil inside a filter too much oil may have been applied last time a filter was re-greased. These reusable air filters are lubricated from outside of a filter (side opposite motor) before use trap smallest particles. However finding some oil in an air filter is not serious problem on its own it can indicate certain underlying problems that are not related to an air filter or engine oil. Our certified mobile mechanics perform home visits in more than 2,000 U.

S. UU. Fast and Free Online Quotes for Your Car Repair.

Jenny Nordine
Jenny Nordine

Award-winning twitter scholar. Freelance sushi practitioner. Lifelong sushi practitioner. Incurable internet expert. Passionate bacon advocate.

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