K&N air filters started off as an innovative product and is one of the original oiled air filters. They are used in the racing industry for peak performance dragsters as well as in commuter vehicles. But how do you clean your K&N air filter without using the official recharge kit?
A K&N air filter can be cleaned with a variety of general cleaning or automotive products. You can then use aerosol oil to make sure the air filter is well-oiled and in as good a condition as if you had used the official recharge kit.
In this article, I’ll run you through how to properly clean your K&N air filter and suggest the best products to use. We’ll also do a step-by-step guide so you know how to best perform each part of the clean to ensure you get the cleanest air filter you can get.
Can I Use WD-40 On A K&N Air Filter?
WD-40 is fine to use on a K&N air filter. WD-40 leaves behind a film when sprayed which can act as rust protection as well as helping get rid of any excess water.
Standard WD-40 will work fine, but to get into all the gaps and fully coat the filter you could look at the penetrating oil version of WD-40. Penetrating oil is a slightly different formulation that is better able to flow into the tiniest of gaps and cracks.
However, WD-40 is not the best choice for applying oil to your air filter. While K&N recommends their own Red Filter Oil, automatic transmission fluid has been used by many in the DIY repair community with great results.
Best Way To Clean K&N Air Filter
K&N recommends that you buy the K&N Air Filter Cleaning Kit to clean all their air filters. This kit comes with Power Kleen and Red Filter Oil.
K&N recommends that you first clean the filter, leave it to dry, and then apply the Red Filter Oil. This is referred to as a recharge of your air filter.
The first step is to liberally coat the air filter with Power Kleen. Wear gloves and apply the Power Kleen to both sides of the filter. It is important to not let the Power Kleen dry, so do not allow the filter to dry in the sun. After ten minutes, it’s time to remove the Power Kleen.
High-pressure spray can damage the filter. The filter has a front and back, the front is doing the filtering and so will be the dirty side. Spray water through the back part to push the dirt and debris out the front.
After that, take the filter and bump it against a solid object to dislodge any remaining stubborn debris. This will also help remove excess water. Leave to dry in a warm area but do not use a heat gun or other artificial means as this may damage it.
After the filter is completely dry, lay the filter down on a flat surface and coat the air filter fins with the Red Filter Oil. Spray in a horizontal fashion and then in a vertical fashion to ensure full coverage of the surface. The red tinge of the K&N oil will show you if you’ve covered it.
Leave the oil to dry on the filter and mop up any excess with paper towels. Too much oil can clog the filter but there should be enough so that the air filter can work properly.
Alternatives Products To Clean A K&N Filter
There are many products that will work just as well as the official recharge kit for your K&N filter. Some of these come in aerosol form and some in liquid form, you can use a pet syringe or baby syringe to have more control over how to apply the liquid.
One of the most common products that you’ll have lying around your garage which will do the trick is ATF or automatic transmission fluid. Research what is the best brand of ATF for your vehicle, but generally, most of these products are the same and will do a fine job.
A variety of other cleaning products will excel in this situation. Simple Green is a popular cleaner and degreaser that should work a treat to clean your K&N filter.
Other products from automotive product manufacturers like Castrol’s Super Clean have been shown to make a K&N Filter look new. Generally, you’re looking for a degreaser and general cleaner to get the most junk out of your air filter.
Take a look at this helpful YouTube video that shows how to clean a K&N Filter.
After rinsing with water, regular dish soap and warm water can help dislodge any final stubborn grease or oil remaining.
To finish off the cleaning, you need to spray oil on the filter similar to K&N’s Red Filter Oil. Virtually any aerosol oil spray will do the job.
You can also use Valvoline’s multi-vehicle ATF that will work for most makes and models. Apply it to the air filter’s fins either via spray or application via a syringe. WD-40 will also work in this situation.
Use one drip for every pleat on the cone-style filters and the oil will spread into the filter. The flat air filters can just have the aerosol oil sprayed straight onto them.
How Often Should You Clean A K&N Air Filter?
K&N suggests cleaning your air filter after every 50,000 miles in normal driving conditions. They suggest extending that to 100,000 miles for the oversized, conical High-Flow Air Filters.
A dirty filter will not only reduce airflow and hinder engine functions but also lead to lower fuel efficiency.