Car Care Advice

Car Engine Air Filters: A Complete Guide

How to change an engine air filter

Replacing Your Engine Air Filter Is A Beginner Job for Most DIYers. Here’s Everything You Need to Know to Replace Your Engine Air Filter at Home.

  • DIY Difficulty Level: Beginner
  • Time Required: 5 to 15 minutes
  • Tools & Materials: A new air filter ($20-$40+). You may also need basic screwdrivers or wrenches, but will likely need no tools at all.

What Is the Engine Air Filter?

Your engine breathes air the same way you do. While you breathe air through your nose, your car breathes in through the air intake system. This is a series of tubes that bring air from outside your car into the engine. A simple filter, usually made of paper, sits near the beginning of your engine’s air intake system. It makes sure that only clean air goes into your engine, with no dust or debris that might cause damage to sensors or the engine itself. It works rather like the face masks we all got used to wearing in 2020.

For modern cars, changing the air filter has been shown to increase gas mileage by 10% and boost acceleration by as much as 11%.

Is It Safe to Drive with a Dirty Air Filter?

When you breathe dirty air, you cough, sputter, and get dirt into your lungs. That’s also what happens to your engine when you drive with a dirty engine air filter. The engine may run rough. You might lose power or fuel economy. The check engine light may turn on, particularly if your engine misfires. The trouble code may also indicate a lean condition, which is a sign that your mass air flow sensor is dirty or has failed.

A mechanic or oil change shop can replace your engine air filter for you, but it’s so quick and easy to do, you might as well save some money and do it yourself.

How Often to Change Your Engine Air Filter

Clean and dirty engine air filters

If your air filter looks like the one on the right, it needs replacement right now. This is the one I took out of my recently acquired Ford E250 van when I cleaned the mass air flow sensor to cure a check engine light. When I saw this, I bought a new air filter and replaced it immediately.

Generally speaking, you should replace your engine air filter every 12,000 to 15,000 miles. This may vary, however. Check your vehicle maintenance schedule in your owner’s manual, and go by what the manufacturer recommends. If you find yourself driving on a lot of dirt roads or putting your car under high levels of stress, check your air filter more often than the factory recommends. 

Our automotive specialists recommend changing your air filter once or twice a year, regardless of mileage, to make sure it’s operating properly. If you’re looking for an easier way to keep up with routine maintenance items, such as when it’s time to replace your engine air filter, the FIXD sensor and app will keep track of all this for you on the maintenance timeline inside the app. You’ll automatically be alerted when it’s time for a new filter, oil change, tire rotation, car battery, and more so you never forget.

What Are Common Symptoms Indicating You Need to Replace Your Engine Air Filter?

If your engine air filter is dirty, you may experience the following:

  • Loss of power
  • Poor fuel economy
  • Rough running
  • Check engine light

Keep in Mind

Remember to always follow the manufacturer recommended maintenance schedule, and change your engine air filter as advised for your particular make and model.

Since it’s generally located near the engine air filter, now is a good time to clean your mass air flow sensor. You may also want to clean the throttle body while you’re in there since it’s in the air intake system as well.

How It’s Done

Step 1: Buy a new engine air filter.

The cost to replace an engine air filter is relatively cheap, normally under $20, and they’re easy to buy online or in your local auto parts store. There are some high end brands that can go up to $50, but these are extremely high performance, and not really necessary if you aren’t doing a lot of heavy stress driving. 

Remember to look up your vehicle’s make, model, and engine size before purchasing your air filter. Air filters are specific to engine size, and each model of a car can have various engine sizes, so be extra careful when you are looking up this information. You can find this information in your car owner’s manual or online.

Step 2: Find your engine air intake system.

Ford E250 van air intake system

The exact location varies from vehicle to vehicle, so consult your manual to find it in your car. You can generally find your intake system under the hood near the front of the engine bay. In my Ford E250 van, it’s the big cylinder right on top of the engine. (The fact that the outside was so dirty was my first clue that the filter was dirty, too.)

Step 3: Open the air box.

Open engine air filter box

The airbox is a large square or cylinder in the air intake system, located near the front of the car. This box contains your engine air filter. In most cases, no tools are required to open it. One or more simple clips that you can open by hand hold it closed, as shown here. In rare cases you may need a simple screwdriver or wrench to open the air box.

Step 4: Remove and replace the air filter.

Remove engine air filter

Once the air box is open, you can pull the filter right out. Remove the old one, and install the new one in the same direction and orientation as the old one.

Step 5: Reassemble the air intake system.

Now that the new filter is in, put together everything you took apart, and you’re done.

Claim Your Custom Maintenance Schedule

Get the FIXD Sensor and free app today for a custom maintenance schedule based on your make, model, and mileage. Never miss important maintenance again with automated maintenance alerts! Learn more at fixd.com.

Justin-Hughes

Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

Justin Hughes
Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

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    16 Comments

    1. You don’t mention the option of reusable replacement air filters, such as K&N brand.

      1. Great point! Thank you, Allen 🙂

    2. I most certainly disagree with your statement on Fram filters leading the field in air filters maybe purchased wise but certainly not the best air filter!

      1. Thank you so much for your feedback, Paul! We would love to know what you think is the best air filter out there.

      2. That depends what you consider “Best”. Fram filters tend to clog sooner and require replacement more often because the filter smaller microns size particles – a good thing if you want the engine to perform over 300k miles.

    3. Good to find support for DIY. Bravo to you guys and gals.

      1. Aw shucks! Thank you so much, Gretchen. That makes our day to hear 🙂

    4. Thanks. Very good insight.

      1. Thank you so much for the kind words, Al! 🙂

        1. I can’t get my engine air filter housing to close securely and I need help

          1. Then it’s either installed incorrectly or is the wrong filter for your particularly engine. Some models had different filters in the same production year.

    5. Thanks good info, most people just look at the price, and as long as it fits.

      1. You’re welcome, Santiago. 🙂

    6. Thanks Fixd for the info on how to replace your Air Filter.

      1. You’re welcome, Ethel! 🙂

    7. One way to extend the life of an engine air filter is to shake it blow out heavy debris like bugs. If you hold the filter up to the sun or a bright light and can barely see light coming thru it, it’s time to replace it as it has caught a great deal of fine dust.

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