K&N, Can't & No-way

[CharlesBrown]

I've seen a number of posts here and on other forums extoling the K&N filter. Sorry I ever bought one but never again! It was not used on the vett. but on a 4.6L Ford engine. It all but shut down the sensors in the ilnet air stream causing won't-run-after-start condition. It also caused a $400 bill from my Ford dealer to clean the system. I've nothing against K&N (maybe a warning like on the cigarette packages) just posting for the guy who reads some of these posts and wants to get a few more cheap horses. There could be a price to pay. Lets say the K&N causes no initial problems, how can you be sure you've used the right amount of oil the filter cleaning requires? An excess can only go one place.

 

[JEFNLSA]

Sorry to hear of your dilemma but...

You're only supposed to "mist" the filter. I have 3 K&N's (which I've cleaned & re-oiled twice already) on my SLP unit and I've had no issues w/ my car. The key is not to over-oil them...as clearly stated in the instructions included in the K&N kit.

 

[minifridge1138]

I'm sorry for your bad luck.

I've put K&N air filters on all of my cars and had absolutely no problems.

Don't over-oil them and they will work very, very well.

 

[Hib Halverson]

If you "over-oil" any oiled-cotton air filter, be it a K&N, a Green, or any other brand, you'll have problems with MAF or IAT sensors.

This is why most of the major mfgs. of such products tell you not to over-oil them.

 

[Black Bart]

I'm sorry for your bad luck.

I've put K&N air filters on all of my cars and had absolutely no problems.

Don't over-oil them and they will work very, very well.

YEP kinda like MacDonald's having to put a warning on the coffee warning people it is hot.
Some people will screw it up even after you put the warning on.
I have been using a K&N for 7 years with NO problems,
Your problem is NOT the fault of K&N you were the one who over oiled it.:W

 

[bradslt5]

sad to say but thats true .it not the filters fault. just realie what others have told you and mist them . they really in the long run save money . paper filter for the zr1 37 dollars change every 10k . kn 54 dollars and thats it. i have 142k on my zr1 471 for a paper filter for the same period . and more hp out of the k&n .glad i bought one . but to each his own

 

[CharlesBrown]

Perhaps you misunderstand... The NEW filter, right out of the box, did the damage. Surely you don't think I would re-oil something that cost me that much to repair so it could happen again.

 

[JEFNLSA]

Perhaps you misunderstand... The NEW filter, right out of the box, did the damage. Surely you don't think I would re-oil something that cost me that much to repair so it could happen again.

Well, you didn't clarify whether this had happened due to re-oiling so I/we just assumed. I find it hard to believe to that a "new" filter, fresh out of the box & pre-oiled, would cause you these problems. If so, I'd take it up w/ K&N because all the negatives I've read in regards to K&N can be tracked back to consumer over-oiling. So, this is a first for me....and obviously a last for you.

 

[JEFNLSA]

Lets say the K&N causes no initial problems, how can you be sure you've used the right amount of oil the filter cleaning requires? An excess can only go one place.

This statement most likely added to the confusion. Reading "that" makes it sound like the problem/s you incurred happened after the filter was cleaned & re-oiled.

 

[Onebadelf]

Sorry to hear about your K&N problem. I have a K&N on my 81 Vette and my 02 Mazda and am thankful that I have had no problems with either auto. Best of luck on your choice of breathing.

 

[TedC]

Here is what I've discovered. My used 1988 came with a K&N filter, and my used 1989 did not. Both had 50K. The 1988 had a film inside the intake, with dirt collecting on the MAF screens. The 1989 did not. When I asked my local covette performance shop which filter should I use, they recommended a paper filter on a stock C4. They have seen similar situations like my 1988, which does not happen when using a paper filter. So if you feel the extra air flow with a K&N is required, then make sure you oil it properly (not too much, and not too little). While cleaning the K&N, I installed a paper filter, and noticed no difference in performance. When I installed the clean K&N, I noticed no difference in performance using stock auto shift points.

 

[puppyfang]

Gave up on K and N

Just wanted to give my thoughts on this, used k and n for years and then just quit, did a little testing with a mustang that I had on a dyno, sorry to say but not enough difference to matter, then I was talking to a few good race mechanics and they said unless you change the throttle body and "feeder tube" (or supercharge or ram air) you can only get so much air through this so why waste the money on a k and n, more air in the front does not mean more air at the back, so far all my cars run just as good on a original filter, just my 2 cents on the subject....thanks!

 

[TedC]

Some points to consider based on actual air flow studies on a L98 C4. A stock 5.7 liter engine at 80% volume efficiency requires 426 cfm at a limit of 5250 rpm. The stock L98 lid with stock paper air filter can flow 648 cfm, enough for 6400 rpm at 100% ve. A stock MAF with screens flows 529 cfm. Without the MAF screens, it jumps to 711 cfm. If you remove the MAF screens and grind down the cooling fins, it will flow 750 cfm. Those $50 air foils add 17 cfm. I'm sure there is some HP gains even on a stock L98, but from my own testing, they are over rated. That is why the second L98 vette I purchased had to have the better rear axle (3.07 vs 2.59).

 

[jimmac28]

I agree, for the very small performance gain, I don’t think I’ll risk any damage on any of my cars.

I quit using the K&N filter after a Pontiac mechanic showed me on my year and a half old 2003 Grand Am with only 12000 miles on it, the slight film that was building up and telling me if they can prove that K&N was the cause of any problem I might have, my warrantee would be invalid. So in went the paper no more K&N.

My 94 convertible has had nothing but AC filters in it since birth and everything is spotless.

 

[nelson84]

I have notice all the problems or no extra hp occured on a ford?

 

[Red Vette]

I noticed that this thread was quoted in the Corvette Forum with the same kind of responses. I too purchased the K&N system for my 94 after I changed the filter just before putting ithe C4 into storage. I replaced the old filter with a paper filter, thinking the next change would be the K&N. Now I am really in a quandry, do I make the change or not. I definitely will not make the change in my 02 coupe. I will probably dig out the receipt and see if I can return the merchandise for exchange for paper filters. I was hoping Hib would say yea or nea about the K&N, as I value his judgement. Thought Junk might have an opinion also, as he usually is right on the subjects he responds to. Since it is at least 3 months till the C4comes out of hibernation, I have time to reconsider the K&N. I hope this thread continues with discussions for pro and con. I know a lot of us still don't have enough info to make a clear decision. The other forum had some interesting stuff on the amount of dirt filtered out. Paper did better.
Since I mentioned the C5 in this post, I hope Remo will count this as my weekly contribution to the C5 forum. If not, then I will have to come up with something useful for a C5. Maybe I can reprint Patrick's ode to his Z06 from last year.
Barrett

 

[jimmac28]

Here is an interesting read on filters.

http://www.duramax-diesel.com/spicer/index.htm

 

[TedC]

jimmac28, interesting air filter tests. The point of this thread is that if you really need the improved air flow of an oil based air filter like a K&N, then make sure you oil it properly, and watch for any oily film buildup. For my stock 1989, I'll go with my local corvette performance shop recommendation and use paper. The ability of paper to trap dirt is an improtant factor for me, and the air filter is an easy maintenance item to replace each year. Threads like this provide good points that educate all of us. Glad to see it can be done without emotional comments on either side.

 

[WhalePirot]

if you really need the improved air flow

this points to another factor: what we want the car to do. Are we looking for high performance transportation that will endure with minimal problems, or a damn-the-dirt, I want an every (perhaps, if the engine REALLY can use the air) ounce of performance, machine.

When I initially spoke to my engine builder, I scratched my head at his questions, "What do you want the car to do?"; "What will you use it for?". After some guiding from him, I made decisions and am very pleased with the result and the cost.

Like the technical article states very late, in reference to the off-road racers, all choices are a compromise of some sort. I always knew that, but it struck home real hard when I took my hot street Vette to an open-road track day at Buttonwillow, run by a small group of car nuts, called Speed Ventures.

I quickly discovered that, a) my car was an awesome STREET machine and quite reliable, and b) some of my 'street' compromise choices had no place on the track; being different goals, demanding different choices.

Example: 'Track brakes' work best on the track, but not on the street, and vice versa. The track parts work best when hot, under hard, repeat braking, but on the street, when relatively cool, they don't stop so well, while costing a LOT more.

Run this scene with every part you are planning to buy and your result will be optimized for your driving and wallet. I made some mistakes, many openly mentioned on CAC, often as a minority opinion to those who subscribe to the marketing claims. Hey, it's your cash, not mine. Luckily, I had some guidance from a longtime Corvette owner, enthusiast, Corvette mechanic and shop owner who was direct and honest about what worked and what was a waste of money. While often I ached for more stickers for my toolbox, I followed his advice and am pleased.

My Vette has a K&N, for now, because the intake structure does not allow a paper filter, but a cone.

 

[Black Bart]

I have a friend that built a street rod back in 1963 it has four carburetors with velocity stacks sticking out through the hood. NO BREATHER OF ANY KIND.
The car has been driven 185000 miles and the engine is fine and NO oil consumption.

If you run your vehicle on gravel roads then you need to protect it from all the dust in the dry season.
Otherwise a filter is not as critical as some think.

I have a K&N on my engine and I sleep well at night but then with over 1000 HP I know it won't last forever regardless of the air filter on it.
If you drive your vette like a granny the stock air filter is OK if you have a performance cam and Intake on it and a stock air filter then you are not benefiting from the mods like you could be.

The point that I'm trying to make is this is not a one size fits all sort of thing.
If you have a stock engine and drive it Conservative stock filter is fine.
For some of us it SUCKS