Topic: K&N filters--anyone have them?

[Mitlov]

My modded Jetta (which I bought used, already modded) has a K&N filter instead of stock.  Are there any real advantages to this over the stock filter?  Any disadvantages?

I read that K&N filters need to be periodically washed and oiled.  Anyone had experience doing this?  Is it an easy task, or a grubby one?  I don't have any sort of wash-room or utility sink, and so I'm hesitant to do anything that would really gum up my kitchen sink or bathtub.

If washing the K&N filter is a dirty or energy-intensive process, I was debating going back to a stock filter, at least until we move somewhere that has a sink in the washroom or garage.

Any and all input is appreciated.

[mdxtasy]

When I had one, I would use the garden hose to rinse out (no nozzle)...and then spray on the oil afterwards.  It wasn't hard.

[dr_spock]

I have one in my VW.  It is not difficult to wash it and re-oil using the K&N cleaning and oiling kit.  You can wash it outside with a garden hose in a very gentle flow.  Too much pressure will damage the cotton gauze.   Don't over oil it since that can mess up the Mass Air Flow sensor if oil get sucked on to it. 

[initial_D]

I have one in one of my cars. The shop where I do my maintenance clean & re-oil it for me for $10.

[tpl]

It is VERY important not to add too much oil as it gets on the MAF as dr_spock says.  It is possible to clean the oil of the MAF oneself but I have been told its a fiddly job. I suspect that dealers just replace it.  I was tempted when I had my chipped Audi A4 1.8T and resisted those extra couple of BHP just because of that problem.

[mrthompson]

I failed an emissions test a few years ago because of the K&N air filter I had in my Cherokee.  For the cost of a K&N, one could afford to replace the stock air filter twice a year for several years (in most cases).  They're a waste of $$$ in my humble opinion. 

[PJungnitsch]

I got one (at least a K&N type) with my Weber carb conversion. I bought the K&N reoiler kit and will try the process today. I don't have any garage facilities either, so we'll see how grubby the bathroom gets.

It does make the intake howl, I like that quite a lot. Shouldn't have watched Vanishing Point.

[Mitlov]

I got one (at least a K&N type) with my Weber carb conversion. I bought the K&N reoiler kit and will try the process today. I don't have any garage facilities either, so we'll see how grubby the bathroom gets.

Feedback would be appreciated.  Chemical residues around the house are a non-starter for me, because my 14-month-old gets into everything, and licks and bites everything. 

[ovr50]

I have had a K&N but I think there are trade-offs, as with many mods.

Overoiling is clearly a problem, and the remedy can be costly if you mess up the MAF.

Some swear they are great with little downside; others won't put them in their vehicles. I can assure ppl that I will NOT be putting one into my new BMW.

[articsteve]

My view is that for cold intakes they are obviously a must, but for applications where it just replaces the OEM filter in the airbox it's of no value because the oil in the K&N does not remain constant.  The negatives of allowing more than normal dirt particles in the motor because of inconsistent cleaning effect (oiling) more than offsets any benefits of extra air intake.

Air in = air out.  If you increase intake you must increase the exhaust flow for a real benefit.   

[Mitlov]

Air in = air out.  If you increase intake you must increase the exhaust flow for a real benefit.   

How about the vice versa situation...my car has a performance exhaust (Neuspeed).  If I go from a K&N filter back to stock, I might lose a few horsepower (maybe even a half-dozen), but is the end result in any way bad for mechanicals?  I'm fine with losing a few horsepower in the name of convenience and long-term reliability, but I was wondering if the "unbalancing" of a normal filter with an aftermarket exhaust could have any bad ramifications.

[articsteve]

The greatest gains are made with improved exhaust flow when your motor's fuel is controlled by fuel injection.

Sleds are a great example.  Almost all HP gains in sleds (snowmobiles to you Mit  ) are done on the exhaust side.  Since most sleds now are FI then no need to tinker with the fuel/air because that is generally automatic.  Now if they are carbed then one needs to physically get in there and change the jet size.

So IMO, there is no issue with going back to a normal filter because the FI system will automatically compensate for any change in air/fuel ratio.  And I think we're talking SLIGHT between a paper unit and the K&N; slight to NIL actually.   Put back the stock exhaust and then you'd notice a difference.

[Loudpedal]

I've used K&N's in my last few vehicles.  Sounds crazy, but I think that over time of use, engines that have used K&N filters may burn oil.  I don't think that they truly filter out all grit, as does a stock paper filter, and over time that grit may take a toll on the cylinder walls.   I have no scientific data to support obviously, but just extra oil bottles in the garage. 

K&N's do make great sounds when you cut-pile the loudpedal.   

[HeliDriver]

I've got a UNI foam filter, and generally find it to be a pain in the ass. I'd much rather just use a paper filter and toss it in the trash when it's done. I could live with the 1-2 HP loss. 

I usually wash the filter in a bucket in the back yard, then pour the oily, grimy water out in the back alley when nodody's looking.     

Unfortunately, I'm stuck with the UNI because it's the only thing that will fit in the aftermarket airbox of my cold air intake system. And I'm not about to give up the cold air intake. 

[barrie1]

I have run a K&N filter for a NO. of years on top of my truck engine. Its about 5" high as I run a Hir-rise aluminum intake with a Holly 700 Speed bore double pump carb on top. It gives me the air flow I want for my engine without being over sized as well. Good for racing and a lot of street use as well. I use a small shallow type of wash pail and buy about 3 bottles of their cleaner to keep pouring over it and reclaim it as well. Once its clean enough I rinse it with cool water and hang to dry as well.  I probably lose about 1/2 of one bottle every time but keep on useing the same stuff. When dry I spray it liberally with their oil and re-install on top of the engine again.I do get a little more Hp from useing it but my oil dirties much quicker as well in all honesty. The same filter in a air cartridge from Canadian Tire is around $10.00. It the biggest one they sell actually and does work quite well as well also. I have been rotating the 2 this year and the dry cartidge is in there at the moment. Seems just as good actually. I would be leery on some of the newer engines as per the sensors can be affected quite bad so think it out before useing on your particular engine. Mine cost me around $90.00 new and OK but not something special in my book. 

[maritime_storm]

My view on them is that if they allow more air in by being less restrictive than they have to be letting more dirt in at the same time.

[rrocket]

I've used these for as long as I've had cars, and is generally one of the 1st mods I make.  On the Echo though I'm using one of the Air Hog brands.  But back to K&N. 

The "new" way I've been cleaning these for the last couple of years is to get a bucket.  Put a scoop or 2 or Oxy-Clean in the bottom of the bucket.  Put the filter in the bucket so the bottom of the filter is on the bottom.  Pour in a liter or two of Club Soda.  The mixture will foam, and the foam pushes the dirt out of the filter.  After 2-3 minutes I take it out and spray it of...but spray from the backside so you force any remaining dirt out through the top of it.  This way works very well and is very easy. 

[PJungnitsch]

I got one (at least a K&N type) with my Weber carb conversion. I bought the K&N reoiler kit and will try the process today. I don't have any garage facilities either, so we'll see how grubby the bathroom gets.

Feedback would be appreciated.  Chemical residues around the house are a non-starter for me, because my 14-month-old gets into everything, and licks and bites everything. 

Not bad at all. Sprayed the filter with the cleaner, let it sit in a small flat rubbermaid container (2 gal?) while it 'digested' the oil and dirt (covered with a lid), then rinsed it out under the tap. Let it dry overnight, then sprayed it just now with oil over the container to catch the overspray.

Having a dedicated container helped a lot in keeping the bathroom clean, and I'll store the cleaning kit in the same container.

That said, I think I'll see if I can adapt my stock filter housing to the Weber, I've heard of the better dirt filtration with paper, same as has been mentioned.

[Cord]

PJ, FWIW, consensus opinion on the SV650 forums seems to be that the stock Suzuki air filter flows more air than the K&N.

[PJungnitsch]

PJ, FWIW, consensus opinion on the SV650 forums seems to be that the stock Suzuki air filter flows more air than the K&N.

That's interesting. This is for my old truck though, replaced the carb last month and a K&N type filter came with it.

Original engine bay:



The complicated stock carb that finally bit the dust:



Fitting the new Weber 32/36:



And installed with its pancake style oiled air filter:



It IS nice to be able to see the engine.