Clean and Re-Oil your K&N (or K&N style air filter)
DC CarCare has been selling K&N Filters for several years. One of the most asked questions is how to clean and re-oil the filter. Of course instructions do come with the filters, but sometimes it helps to go over some of the fine points, so here we go with your most asked questions and our answers..
1. Does the filter come ready to use?
Yes, the K&N filter comes pre-oiled and ready to use. I have seen some oiled FOAM filters from other manufacturers come WAY over-oiled, but not the K&N. You can put the K&N to use immediately.
2. How long will the filter last?
K&N has a "Million Mile Warranty" or basically for the life of your vehicle. K&N says their filter will go up to 40,000 or more miles before needing cleaning. K&N also says that you should not clean your filter more than 25 times or the cotton filter media can become to worn to filter effectively. If you divide 1,000,000 by 40,000, you get 25....works out pretty nice doesn't it!
3. How do I know when to clean my filter?
The best way is to use an air restriction gauge like most bigger diesel trucks have. But without this, you can pretty much see if the filter is getting plugged up. The old drop light held behind the filter is NOT a very good test, but for sure, if you can't see light through your filter, it should be cleaned. I recommend to my customers that they clean and re-oil at least once a year, or check it every 30,000 miles. If you drive on a lot of dirt roads, or race on dirt, then you may be cleaning your filter much more often. In that case, consider a K&N "Precharger" filter wrap to keep out the biggest dirt chunks and cut down on how often you have to clean. I have proven in dyno testing that a foam pre-filter, even those sold by K&N will hurt the HP gain that the K&N filter provides, but to those racing on dirt, this is not that big of a deal.
4. How do I clean my filter?
K&N recommends that you start by gently tapping the
filter to dislodge any big chunks. Go easy, you can damage the filter if you hit the
actual filter portion, only tap on the edges. Then you can use a soft bristled brush
VERY GENTLY to remove big things that are still left on. NEVER try to brush on the
filter media itself, only on the stuff stuck to the filter. Better to leave a few
chunks than tear the cotton filter media.
5. How do I oil my filter?
K&N oil comes two ways, a squeeze bottle of oil or
a spray can. Remember you are oiling the OUTSIDE of the filter, the way air goes
into the filter. With the squeeze bottle, put one thin line of oil on each pleat,
only on one side please. With the spray oil, use this method: with the oil
spray at about a 45 degree angle to the pleats, spray across the top of one pleat onto the
side of the next pleat and put one quick line of oil on each pleat. NOTE that the
spray oil comes out in a sputtering stream rather than a fan spray, like paint.
6. What about manufacturer's claims that the warranty is void? Why do they say this?
K&N says that this is not legal. Manufacturers cannot void your warranty for using a K&N filter. The only possible problem comes when a K&N filter is over oiled. Some of the excess oil can get in the air stream and contaminate the MAF sensor or other sensors downstream. This is a much worse problem with oiled foam filters than oiled gauze. Foam can hold much more oil and it can seep out for weeks or months. A properly oiled K&N filter has never harmed any sensors or caused any problems according to K&N.
7. I bought a K&N style filter... is it as good? Is it serviced in the same way?
There are at least two companies that provide a K&N "style" filter. I think that they are probably of good quality, but I don't think these companies provide the exact fit replacement filters for factory air boxes. Instead they offer generic filters for aftermarket applications or maybe a few of the most popular vehicles. You should follow the manufacturer's instructions for cleaning, oiling and service life if you have one of these filters. As a rule, though, they can use the K&N oil and cleaner to maintain them. And what applies to K&N applies to K&N "style" filters.
There is more, and to that end, I provide you with this link to a comprehensive page by K&N on their products: http://www.knfilters.com/facts.htm#FACTS