How To Know When It's Time To Change Your Car's Air Filter

Your car's air filter may not need checking and changing quite as often as, say the oil, but you definitely should change it from time to time. This can be done in a shop or at home if you're comfortable with it, but failure to stay on top of the filter could result in a drop in gas mileage.

It's recommended that you change out the air filter at least once every 30,000 miles, though if you live in an area more prone to dust and dirt in the air, you should swap it out closer to 15,000 miles or so. But that's for general maintenance and regular wear and tear.

Depending on the situation, your vehicle, your environment, and loads of other factors, your air filter may not always follow that 15,000 to 30,000-mile guideline. In the event that you suspect something might be up with your air filter (despite it not complying with the typical mileage) or you aren't sure how many miles it has left, there are telltale signs that can still give you a heads-up.

Not all of the bad air filter indicators necessarily mean the filter needs changing. Still, if you experience any of these (or a combination of them), it's a good idea to check it out anyway.

1. Open your car's hood (when it's parked in a safe area and turned off, of course) and open the air filter housing, then remove and inspect the filter itself. If you can't see any light through the filter material, it's time to install a fresh one.
2. Various sensors may detect filtration issues, which don't have their own indicators, but they can cause the check engine light to turn on. So, if the light is on for no apparent reason, look at the air filter.
3. A dirty filter can also cause your engine to make an assortment of irregular noises, such as "coughing," "popping," or "sputtering."
4. Black smoke from your car's exhaust or the smell of something like raw or unburned fuel are also indicators of airflow (i.e., filter) blockage.
5. Unexpected performance issues such as stalling when slowing down, feeling rough or inconsistent when speeding up, or sputtering or lurching when driving may also result from an air filter problem.

If you experience some of these issues and your air filter doesn't appear to need changing, or if you change the air filter, but the problems persist, you should consider taking your car to a professional for an assessment.