How To Replace A Car Air Filter

Tuesday, 18 February 2025

Changing an air filter in a car is an easy and quick motor maintenance job. It does not require any professional training or skills, and all you need is a few tools and a few minutes to replace a car engine air filter. It is one of those common car issues that you can fix yourself.

What does an air filter do in a car?

Whether you drive a petrol or diesel vehicle, the fuel needs to combine with oxygen in order to work effectively. Air filters ensure that any kind of debris, pollen or dirt in the air does not get into the vehicle’s engine. The cleaner the air is that reaches the engine the more efficiently the car will run. Over time air filters get dirty and become less effective. If air filters aren’t changed regularly, the engine is more likely to be damaged.

Air filters are made of paper, cotton or foam, and are fitted into a housing within the engine bay. These housings are usually very accessible, making changing a car air filter quite a simple job for a car owner.

When to change the air filter on a car

Opinions vary on when you should replace your air filter – every 30,000 miles, 3-4 years, 15,000 miles, or every year – but the important thing is to check it regularly. If you have been doing a lot of driving, or the weather has been particularly dry, air filters get clogged more quickly. The area where you drive is also a factor. If you live in a rural area you might do more driving on dirt tracks or muddy roads, or if you live in a city, where the air is more polluted, the life of an air filter can be shorter. Your car’s maintenance manual will tell you how often the air filter should be changed.

Air filters are among those parts that have to be replaced regularly in your car.

Air filters and other assorted car accessories

How to replace a car air filter

You can pick up new air filters for between £10-20 at most automotive spares shops.

1. Gather your tools

You should only need a flat blade or Phillips screwdriver, a clean damp cloth and maybe a hand-held vacuum cleaner.

2. Locate the air filter housing

Open the bonnet. Locate the air filter housing (it should be quite easy to get to). In modern cars it is usually located near the top or side of the engine. Release the retaining clips or use the screwdriver to unscrew the fixings.

3. Remove the old air filter

Lift off the cover of the housing and remove the old air filter (note down which way the filter is facing, as it will need to be replaced in the same way).

4. Clean the air filter housing

Wipe the dirt from the housing with a damp cloth, or use the vacuum cleaner if there is a considerable amount of debris. Don’t use compressed air to clean out the filter box assembly.

5. Install the new air filter

Place the new air filter into the filter housing and put the filter cover back on. Secure it in place using either the screws or the retaining clips.

6. Check all connections are secure

Ensure that the air intake and vacuum hoses don’t have any cracks in them, and that the hose connections to the filter housing cover are secure. Shut the bonnet and you’re done!

That’s the whole job of changing a car air filter.

Benefits of changing a car air filter

Replacing a car air filter will have a number of benefits for your vehicle.

Increasing fuel efficiency

The most immediate effect of changing your car’s air filter will be to increase your fuel mileage. You should see an improvement of 5-10% in fuel efficiency, because a clean air filter improves air flow to the engine.

Lower emissions

The amount of CO2 your vehicle emits is going to be significantly reduced with a new air filter. Clogged air filters not only reduce air flow to your engine, but also cause an imbalance in the air-fuel mixture and fouled spark plugs.

Extending engine life

Any dirt or debris that gets into engine parts like cylinders and pistons will negatively affect engine performance. So changing the air filter will help to prolong the life of your engine.

Find your replacement car parts at ASM

With a wide range of used car engine parts available from ASM Auto Recycling, we can help with your search for replacement parts for your car. In our used car parts store you can search by your car registration, make and model and find all the parts that we have available for your vehicle. Plus, we offer a 90-day parts peace of mind guarantee for fitting used replacement engines or car parts purchased from ASM.

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