Why is my K&N drop in covered with a quarter inch layer of mud and grease?

[beavis195]

My truck seemed slower, so I pulled the airbox up to check the filter. The bottom half of the K&N had mud and grease on it. I cleaned it with a screwdriver the best I could, then replaced it. I got to thinking, could the stock intake be plugged with mud, and if so, how do I get to it? Thanks

 

[leenjen]

why not disconnect the intake from the box and drill your airbox with a 3" holesaw?

 

[Gary Steeber]

beavis195
It's normal for the K&N filter to become coated with a heavy layer of contaminates. This is a combination of road/trail dust and K&N filter oil. This layer of dust is actually stated to enhance the filtering ability of the element.
It is not advised to scrap the filter with metal objects, this could damage the element.
Your filter should be cleaned every 10,000 to 20,000 miles with K&N air filter cleaner and then reoiled with K&N air filter oil. Follow the instructions on the K&N filter recharge kit, they are available anywhere they sell K&N products.