Cleaning your car’s air filter is probably one of the easiest jobs you can undertake and a 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.
Cleaning and reusing a car’s 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 car’s air filter, how to clean it correctly, and when to change it out.
What Happens When Car Air Filter Is Dirty?
Your car’s air filter, made from plastic, paper, and foam, may seem like a trivial component; after all, it’s pretty unimpressive to look at. But let’s take a moment to consider what the filter actually does.
A car’s 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 the throttle wide open.
Your car’s 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 year. 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 turbochargers. The turbo helps power output and efficiency. The turbo’s impeller spins in excess of 250,000 rpm, and grit hitting the turbo’s impeller at these speeds will wear the impeller away in jig time.
I’ve been a mechanic for over twenty years; I’ve worked on and seen the damage this causes. Some environments have higher levels of silica, and under these conditions, the damage can happen surprisingly quickly. This type of damage can be expensive to repair.
Settles the air
You know your cars use 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 tubing is mission-critical. It’s known as a Mass Air Flow sensor or MAF. Its function is to measure incoming airflow and signal the PCM (Power-train Control Module). The PCM then calculates how much fuel to add; this is a continuous operation.
Airflow moving around a car tends to be erratic and, therefore, uneven. Allowing large chunks of air to enter the engine would cause the sensor and PCM to make erratic calculations, which is not helpful for smooth running.
Adding a pleated air filter slows down, uniforms, and stabilizes the airflow.
Can You Clean A Car Air Filter With Soap And Water?
Some performance air filters may be cleaned using soap and water. However, these types of filters will resemble a sponge-type material. Standard pleated paper-type filters should not be washed in soap and water; this will affect how air flows through the filter.
Washing tends to damage the fibers and prevent airflow, 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 car’s air filter is absolutely fine. However, vacuum from the direction of airflow; 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 car’s air filter is, as you know, an acceptable practice, but it 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 unsealed roads during the 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:
- 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.
- Reassemble – Cleaning the filter is great, but do replace the filter once per year, which is especially important if your car is turbocharged.
How Much Does It Cost To Replace A Car’s Air Filter?
Air filters aren’t expensive, you can buy most filters for 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 toolless 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.
You can check out the MAF cleaner I use here on the Consumables page.
When Should I Change The Air Filter?
A vehicle’s 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 alike.
Failing to clean the air filter will result in premature turbocharger failure, and that’s quite spendy.
Does Changing Air Filter Improve Gas Mileage
A dirty filter does affect gas mileage. The clogged filter prevents airflow, 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 with a clean, free-flowing filter will make a difference to your performance and, consequently your gas mileage.
Does Changing Air Filter Improve Performance
A neglected dirty air filter will allow dirt to contaminate the throttle body. Your throttle body is responsible for controlling airflow to the engine. A dirty throttle plate is common; cleaning is a simple job that makes a world of difference to how your vehicle performs.
Spraying the throttle body with throttle body cleaner removed grit, dirt, oil, and carbon deposits.
A clean throttle plate results in smoother idling, crisper response, and greater fuel efficiency. Check out the throttle body cleaner I use here on the Consumables page.
A dirty filter restricts airflow, and that restricts performance. The engine can’t make power without oxygen. Any restriction in the oxygen-rich airflow will hamper power output.
Some common restrictions include the following:
- 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.
Does an air filter make a car louder? Some performance air filters will necessitate the elimination of the engine’s standard air filter housing. This increases airflow, performance, and also engine noise.
- About the Author
- Latest Posts
John Cunningham is an Automotive Technician and writer on Rustyautos.com. He’s been a mechanic for over twenty-five years and has worked for GM, Volvo, Volkswagen, Land Rover, and Jaguar dealerships.
John uses his know-how and experience to write fluff-free articles that help fellow gearheads with all aspects of vehicle ownership, including maintenance, repair, and troubleshooting.