How to Keep a Clean Air Filter

With a conventional pleated-paper air filter, cleaning was pretty simple. You took it out, rapped it against the fender of the car a few times, and dislodged all the dirt and debris from it. You could maybe hit it with an air hose, too, and if it was too far gone, you'd just toss it and put in a new filter.

K&N filters, however, use a cotton filter medium that's reusable and will last for the entire life cycle of your vehicle when properly maintained. Not only will they last for years, but they offer superior filtration and lower restriction than conventional paper air filters, for better performance. Cleaning a K&N engine air filter is simple if you just follow these steps.

NOTE: If you can still see the wire screen that holds the medium of a K&N air filter in place, you don't really need to clean it yet.

How to maintain a clean air filter

  • Start by spraying a liberal amount of K&N Air Filter Cleaner on both sides of the air filter. Saturate it and let it sit for at least 10 minutes to loosen any dirt and debris. Don't let it sit so long, though, that the cleaning agent dries on the filter.
  • Use cool, low-pressure water to rinse the cleaning solution and dirt from the filter. There's no need for a high-pressure jet of water or an air hose. If there's any stubborn debris left on the filter, it might be necessary to repeat these first two steps.
  • Shake any excess water from the filter and let it dry naturally. Don't do anything else until the filter is completely dry.
  • Apply K&N air filter oil to the filter medium. Put a bead of the oil along the peak of each pleat and let it soak in so it can wick its way into the fabric. Since the oil is dyed red, it's easy to tell when it's completely soaked in—just look for an even red tint across the entire filter. It will take about 20 minutes for the oil to completely work its way into the fabric. K&N air filter oil is also available as a spray, but this last step of the process is still exactly the same should you use the spray instead.
  • Reinstall the clean air filter in its housing, and you're good for another 12,000-20,000 miles before it needs to be cleaned again!

Advance Auto Parts sells the K&N filter care service kit if you'd prefer to buy a kit rather than separate components to be able to maintain a clean air filter.

Last updated February 28, 2019