With 18,000+ miles over 5 years of some hard driving my MPG’s began to decrease and my filters seemed like a good place to start. The great thing about K&N air filters is their ability to be cleaned and re-oiled with one of their recharge kits for a fraction of the cost of a new filter (or in my case- two filters).
Here are the dirty filters with no hint of the red color K&N is known for.
The recharge kit which comes with a spray bottle of cleaner, and squeeze bottle of oil.
I began by spraying the filter inside and out, drenching the filter media.
I then let them sit for ~10min making sure the cleaning fluid didn’t dry. Just look at the amount of dirt that is coming out.
I then washed the filters from the inside out to rid of dirt and cleaner.
Upon inspecting the filters after the first rinse I was unsatisfied with the cleanliness of the filters. After all, the turbo’s have been sucking the dirt further and further into the filter media. So, I resprayed them and repeated the process. You can still see some dirt draining away during this second cleaning.
I washed them again and set them aside to dry naturally.
I then began re-oiling the filter, just applying oil to the crowns of the pleats.
I then let them set after I oiled them to allow the oil to be evenly absorbed throughout the filter media.
All clean, and dry, and back on the engine.