To Have A K & N Air Filter Or Not

[AZ Mike]

man777: This definitely depends upon the application. In my case where I use a K&N FIPK on my Grand Cherokee, I have a large conical K&N filter vs. a much smaller flat air filter that came stock. So, in my case, I have a MUCH GREATER filter surface area with the K&N than with stock.

jcrome: The airtube on my FIPK is clean as a whistle after 10 years and over 100K miles. You may have different experience than I do.

Hi AZ Mike,

Just curious... how often did you remove, clean, re-oil, and re-install your K&Ns??

As I mentioned before, I ran K&Ns on three sandrails for about 8 years (perfect application). I cleaned them and installed fresh after every trip to the dunes. I also ran "Outer-Wears" (panty-hose) over the top of the K&Ns... this was a big help to reduce sand/dust build up. What I noticed after two seasons (18 trips to the dunes per season or about 9 actual clean, air dry, re-oil procedures) was the gauze fibers started to break down and the spaces in the mesh started to get larger. The oil globules after re-oiling started to get bigger because they did not soak into the gauze as well. These larger "holes" allowed more air flow, but also allowed more dust and sand to enter the carb. After a week end of fun and frolic, I noticed when I took the filter off the carb, I could see little patches of very fine dust that had collected in some areas on the inside top the carb. This was my first indication of a break down in the filtering capability. These filters were subjected to some very harsh and very bumpy, and very exposed conditions to the environment, BUT it did tell me something about the filters. I experimented with the amount of K&N oil I sprayed on the cleaned and dried filters, but obviously, as you must know, the amount of "control" is very limited. I usually allowed the filters to air dry about one week before spraying them, and another week before actually using them.

Since sand railing for me was WOT as much as possible, gas mileage wasn't even a consideration.

My engines were no where near the cost of my close friends running $4,000 and $6,000 engines (back in 1980 that was a junk a change for an engine!!), but I still tried to keep them running trouble free. I was one of very few guys I ran with that didn't have the common blubbering "dirty carb" problems. I think that was mainly due to my diligence about maintenance on my buggy.

I threw the K&Ns away and bought a new set after two seasons. If I still had a sand rail, would I use them again?.. Absolutely.

I wish I had photographed the filters with a macro lens as time went on. I think it would have revealed how the fibers broke down.

In no way am I saying what I experienced was "scientific", but it was just my limited experience with K&N filters in an off-road application.

Anyway, if they work for you... like they say -- If it ain't broke... don't fix it! :D

I only have one K&N; the conical on the FIPK to my Grand Cherokee (well, excluding K&N filters on my personal watercraft). At most, I have cleaned it annually, and less frequently now that it doesn't see as many annual miles. When I do clean it, I allow it to dry for a couple hours so that it will take the oil, oil it, let it soak in for maybe another hour, then fire it up. I have never had filter oil in the tube, have never had a fouled sensor, etc. I have not encountered any degradation of the filter material. However, I will give kudos to K&N customer service....the rubber boot on my first filter started tearing where the hose clamp secures it, and they sent me a new one. A couple years later, the top of the air bonnet where it mounts to the top of the throttle body started developing a tear, and they sent out a new airtube. I have long since lost the receipt; they merely take your word or at most ask for a digital photo of it on your vehicle as evidence that you have purchased one.

[carlexes330]

A litmus test for potential K&N users:

Would you be comfortable running your car without an air filter at all? If yes, then get a K&N filter!

;) You must have run the K&N filter without oil as my engine intake is as clean as a whistle and the filter is filthy and ready for its clean and re-oil excellent product works a treat all the lexus owners here in cali swear by them due to our dusty atmosphere :)

[jcrome04]

Well... if you'd READ through this thread you'd see that there are a ton of Lexus owners that have had dust problems.

ME being one of them.

The K&N I got sucked @$$ straight out of the box. After a while I took the filter off and there was a layer of dust on the inside of the intake.

K&N's work for some people, and I am not one of them. I will never own another K&N or oil filter in my life.

High flow paper or cotton is the way to go. Like AEMs and Amsoil EaA