Clean & Reuse Car Air Filter? (Here’s how)


Cleaning your cars air filter is probably one of the easiest jobs you can undertake and fantastic introduction to DIY auto maintenance. My father ran his own auto repair business and as a kid, cleaning the air filter was one of my areas of expertise.

Can you clean and reuse a car air filter? Cleaning and reusing a cars air filter is an acceptable practice. Performance air filters are durable and are designed to be reused. Although standard air-filters may be cleaned, they aren’t durable and will need to be replaced at the next service.

In this article you’ll learn the importance of cleaning your cars air filter, how to clean it correctly and when to change it out.

What Happens When Car Air Filter Is Dirty?

Air filter

Your cars air filter, made from plastic, paper and foam may seem like a trivial component after all it’s pretty unimpressive to look at. But lets take a moment to consider what the filter actually does.

A cars standard air filter is cleverly designed, it’s constructed with pleated paper. We describe them as paper filters but it’s a highly engineered media. It’s a resin treated paper mixed with synthetic fibers that can filter fine particulars as small as 5 microns.

The pleated media configuration makes a difference too, the pleats increase the surface area which increases air intake capacity, important when the engine is moving with throttle wide open.

Your cars air filter has two main tasks, filter the air and settle the air.

Filter the air

Our environment is filled with silica, they’re fine particulates of rock basically. The fine grains have the ability to destroy your engine, not at once, but over a period of a years. If not for the air filter, the constant blast of fine grit sucked into the engine, would erode the throttle body, intake system, valves and cylinders.

In addition, many modern cars are fitted with turbo chargers. The turbo helps power out put and efficiency. The turbos impeller spins in excess of 250,000 rpm, grit hitting the turbos impeller at these speeds will wear the impeller away in jig time.

Turbo wheel

I am a mechanic and I’ve worked on seen the damage this causes. Some environments have higher levels of silica and under these conditions the damage can happen surprisingly quickly. This type damage can be expensive to repair.

Settles the air

You know your cars uses computers to balance the delicate ratio of gas to air. The measurement is important, an engine won’t run well if it’s getting too much air or not enough.

A sensor inside the air filter trunking is mission critical. It’s known as Mass Air Flow sensor or MAF. It’s function is to measure incoming air flow and signal the PCM (Power-train Control Module). The PCM then calculates how much fuel to add, this is a continuous operation.

Air flow moving around a car tends to be erratic and therefore uneven. Allowing large chunks of air enter the engine would cause the sensor and PCM to make erratic calculations, not helpful for smooth running.

Adding a pleated air filter slows down, uniforms and stabilizes the air flow.

Can You Clean A Car Air Filter With Soap And Water?

Some performance air filters may be cleaned using soap and water. However these type filters will resemble a sponge type material. Standard pleated paper type filters should not be washed in soap and water, this will effect how air flows through the filter.

Washing tends to damage the fibers and prevent air flow, this will result in poor, rough or no running. Black smoke, engine light on and misfiring are all possible symptoms of a washed air filter.

Can I Vacuum My Air Filter?

Vacuuming your cars air filter is absolutely fine. However vacuum from the direction of air flow, otherwise you’ll be trying to suck the grit through the media. Obviously if the filter is thick with dirt and grit it needs to be replaced.

How To Clean The Air Filter Like A Pro

Cleaning your cars air filter is as you know an acceptable practice, but isn’t a substitute for replacement. Your air filter should ideally be cleaned every 15,000 miles and most service intervals will recommend a change every 30,000 miles.

If your environment is dusty, driving on un-sealed roads during summer season for example, will obviously cause a ton of grit inside the air filter. In dusty conditions check and clean the air filter once a month.

Cleaning your filter is easy, follow these tips:

MAF sensor
MAF Sensor
  • Remove the air filter cover – On most cars this won’t require any tools, but some may require unplugging the MAF sensor.
  • Remove and examine filter – Holes, replace filter.
  • Clean filter – Tapping the filter on on a floor will cause the grit to drop off. Tap from direction of airflow. Use a vacuum or soft bristle brush to remove any remnants.
  • Check filter – Hold the filter to the light, if light doesn’t pass through the filter, it’s time to replace it.
  • Clean the housing – Remove grit from the air box, use a damp cloth to trap the dust and grit.
  • Clean the MAF – Spray some contact cleaner on the mass sensor (Optional).
  • Reassemble – Cleaning the filter great, but do replace the filter once per year, especially important if your car is turbo charged.

How Much Does It Cost To Replace A Car’s Air Filter?

Maf Sensor cleaning
Cleaning MAF Sensor

Air filters aren’t expensive, you can buy most filters between $25 and $50, and you can usually add the cost of the filter again for labor to fit. But you can easily fit the filter yourself, in many cases most cars use a tool-less air filter housing.

I would advise fitting it yourself and using the savings to buy an OEM (Original Equipment Manufacturer) filter from the dealer and some electrical contact cleaner for the MAF sensor.

When Should I Change The Air Filter?

A vehicles air filter should be cleaned every 15,000 miles and then replaced every 30,000 miles. For most cars, a new air filter once per year is about right.

However, if your vehicle operates in dusty conditions, you need to check and clean it once a month. Clean air is especially important to turbo charged gas and diesel engines a like.

Failing to clean the air filter will result in premature turbo charger failure, and that’s quite spendy.

Does Changing Air Filter Improve Gas Mileage

A dirty filter does effect gas mileage. The clogged filter prevents air flow and that chokes the engine. Limited performance means the engine needs to work even harder to get the job done and that takes more gas.

Replacing a dirty filter for a clean free flowing filter will make a difference to your performance and consequently your gas mileage.

Does Changing Air Filter Improve Performance

Intake system

A dirty air filter restricts airflow and that restricts performance. The engine can’t make power without oxygen, the faster it can get air inside the engine, the more power it can produce.

Any restriction in the oxygen rich airflow will hamper power output. Some common restrictions include:

  • Dirty air filter
  • Kinked air intake duct
  • Loose turbo charger hose
  • Leaking inter-cooler
  • High altitudes
  • Extreme ambient temperatures

Cleaning, changing or fitting a performance filter will improve airflow, power and gas mileage.

Related Questions

Does an air filter make a car louder? Some performance air filters will necessitate the elimination of the engines standard air filter housing. This increases air flow, performance and also engine noise.

John Cunningham

John Cunningham is an Automotive Technician and writer on Rustyautos.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write articles that help fellow gear-heads with all aspects of classic car ownership, from tires to roof aerials and everything in between.

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