K&N Air Filters - warning

[twins4life]

A little real world information:

I run 3 Dodge Diesel trucks and get routine oil analysis' performed.

With the paper air filters the average silicon (dirt/sand) was 5 PPM. After switching to K&N's the silicon jumped to 34PPM. The included microscope slides of the oil showed dirt/sand in the oil along with increased wear metal.

The K&N's were well oiled and serviced properly. After gently placing the K&N's in the trash can and going back to paper air filters the subsequent analysis showed silicon back down to 5PPM. This occured on two different engines and two different K&N "filters". I think "gravel screen" might be a better name for the K&N's.

Do all those little holes you see in the fabric of the K&N allow dirt through? K&N says no but my testing proved otherwise.

I'm not interested in a K&N war and dont care if you love them or not, but I thought the test results might help others get longer service lives out of those expensive boxers.

[jdiaz]

I used a K&N filter in my R1100RS from around 25K miles until I sold it at 88K miles. Valve clearances never changed, and oil consumption was nonexistent. I used to pull the intake tubes occasionally to check for dirt around the throttle butterflies and never saw anything unusual worth cleaning.

My experience was pretty positive, although I've never felt the need to ante up for another K&N, for whatever reason.

[Cliffy777]

i had a K&N in my last bike but will not spend the cheese this time. i read this:
http://bmwmoa.org/forum/showthread.php?t=4883&highlight=K%26N

[Gnome]

I have talked to many BMW motorcycle mechanics and a lot of them use K&N air filters themselves. I asked them about the debate going on and they almost always tell me this;

"If you are riding a bike in dusty conditions don't use a K&N air filter. But if your riding consists of street,highway, don't worry."

I still believe K&N to be a worthy product. But if it worries you, and you can't sleep at night thinking you may be harming the engine,for goodness sake use a different filter.


I have had great experience with K&N. :)

[jacco]

"If you are riding a bike in dusty conditions don't use a K&N air filter. But if your riding consists of street,highway, don't worry."

Thanks for this thread. I was actually thinking about buying a K&N air filter a few weeks ago, since I thought they were actually better than a paper filter. To me, "better" means either more airflow for the same level of filtering, or better filtering for the same airflow. (I interpret the quote above as "works flawlessly when the air's clean already".) Anyone with another opinion? Parts-per-mil are hard to beat though, assuming the trucks were driven in the same circumstances w & w/o...

Have a good one,
Jacco

[twins4life]

My trucks were run on-highway only, never off road.

Did you follow the link to here: http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

K&N like Amsoil, makes some great claims but in the real world neither company can back up their product.

Personally I wouldnt run either.

My R-1100 was dealer serviced it's whole life till I bought it. The dealer used Amsoil (high profit item). The tranny was balky and prone to miss shifts, after I drained all the Amsoil out and replaced it with a good synthetic (Royal Purple MaxGear 75W-90) the shifting has DRAMATICALLY improved and I havnt had a *single* missed shift. :) My wifes truck was run with Amsoil in the 5 speed, same story as the bike, hard to get into 5th and Reverse. Drain the Amsoil out and put in Royal Purple and just gets smoother and smoother as the miles go by. Actually feels like a different transmission.

Just because a manufacturer has cool slogans and neat little graphs doesnt mean anything. Caveat Emptor

I too am looking for a high flow air filter but the oiled gauze type arent good enough at trapping silicon so the search continues...

[jacco]

My trucks were run on-highway only, never off road.

Did you follow the link to here: http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

Based on those data they even clog sooner than most of the paper filters, so there goes the unrestricted airflow argument. I have to compliment K&N on their fabulous marketing skills. Too bad for us they didn't spend that cash on actual filter R&D. This settles it for me, I'll stick to paper. Thanks again. Jacco