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Why is my lawn mower air filter soaked in oil?

When mowing grass, your lawn mower’s engine is prone to dirt particles and other impurities.

In order to prevent pollutants from getting to the engine, all lawn mowers have air filters. Their work is to trap grime and grass from getting to the interior.

However, regardless of the make or design, the lawn mower’s air filter getting soaked in oil is a common problem. Therefore, knowing ways to handle the challenge is one of the critical skills to possess.

A lawn mower air filter can get soaked in oil because of incorrect maintenance procedures. The most common is turning the lawn mower over with the filter on during repairs.

To solve the oil leakage problem, you need to change the filter and, more importantly, change the way you turn it over while repairing.

Does a lawn mower air filter need oil?

Yes. In order to filter dust and grime, the air filter needs oil. However, when it is soaking with oil, the engine may fail or develop other mechanical problems.

Ways to fix an oil leakage in a lawn mower

If you notice oil in a riding lawn mower air filter, here are some ways to solve the problem.

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Clean the air filter

How do you remove oil from the lawn mower air filter? Washing the filter more often is the best and simplest way of eliminating excess oil from the air filter. Luckily, most brands have air filters that are reusable and easy to clean.

However, before proceeding with this process, ensure that your lawn mower uses an oiled filter. In case it is a non-oiled filter, replace it instead of cleaning it.

Check the user manual to determine what kind of filter you are using. If you do not have the manual, confirm the oil filter’s from the manufacturer’s website.

If the lawn mower has an oiled filter, you can clean it. In this case, you need to have the right tools as per the instructions provided by the manufacturer.

Also, you should have regular soap, oil, and a paper towel. While normal water can work, warm water makes getting rid of the oil easier and faster.

To clean oil from lawn mower air filter:

  • Open your mower’s filter case
  • Gently remove the filter
  • Wash it with warm water and soap
  • Repeat the process until the air filter is clean

Once you are satisfied, use the paper towel to drain excess water before letting it dry in the sun for at least one hour. Alternatively, you can dry it using any method that is available to you. However, any drying method should not change the filter’s form by making it shrink or expand.

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Once the air filter is clean and dry, you can screw it back into the mower. However, it would be best to soak it in a tablespoon of oil to increase its efficiency at trapping particles. To mix oil and the dry filter:

  • Put the dry air filter in a clean nylon bag or a zip bag.
  • Add one tablespoon of clean oil and mix.
  • Remove the filter and place it on a paper towel.
  • The paper towel will absorb all excess oil.

Screw the air filter back to your lawn mower. The cleaning process should not be a one-time activity but a maintenance routine, especially if you use the mower often.

Replace the air filter

If there is oil in a lawn mower air filter even after cleaning, you should replace it with a new one. Luckily, you do not need any special skills to replace the filter in most lawn mowers.

While there are universal air filters for lawn mowers, it is advisable to be specific when buying. If possible, only buy one that is either from your mower’s manufacturer or a generic one made specifically for your mower’s model.

To replace the air filter:

  • Open the mower’s filter case
  • Remove the old air filter.
  • Unbox the new filter
  • Please put it on the oil filter’s case.
  • Screw the filter case back

Apart from replacing it because it is soaked in gas, the process should be after every season. However, if you use the lawn mower more often, you should replace it after 25 hours of working.

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Contact a professional for a comprehensive check-up

In some cases, the precautions highlighted above may not solve the problem. In such a case, it is advisable to contact a professional.

Unlike maintenance routines, a professional will examine more technical issues that may trigger the loan mower to soak the air filter with oil. Fortunately, the chances of consulting a professional are minimal, thanks to the efficiency of the above routines.

Learn how to flip the lawn mower correctly

The probable reason why the lawn mower air filter is soaked in gas is flipping it wrongly when repairing. If you turn the engine on the wrong side when checking underneath, the engine oil will soak the filter.

Fortunately, you can flip and repair the mower without soaking the air filter with oil. Some of the key guidelines include:

The spark plug should always face upward

When repairing your mower, avoid engine oil spillage by ensuring that the spark plug is facing upward. This way, you will repair the lawn mower without any spillage.

Only flip the lawn mower when it is out of gasoline

In case you do not know where the spark plug is on the mower, you should only repair or flip it when it runs out of gasoline. In this state, it is impossible to soak the air filter with engine oil.


If your lawn mower’s air filter is soaked in oil, you should follow the maintenance routines highlighted above.

Apart from solving the problem, the steps are ideal for making your grass cutter effective. However, if you suspect the problem may be more serious, contact a professional.

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