Oh crud. There's a K&N air filter in my car.

[theaveng]

I am selling the K&N filter I removed from my insight. Cost is $45 (25% off) with free shipping. The filter has been thoroughly cleaned, though it still holds the K&N-supplied oil (which removes dirt from air). Estimated miles: 70,000; cleaned only once; yesterday. By buying this you're helping payoff my $1100 bill for a damaged oil pan & damaged hood.

[original post]

There's a K&N in my car. I just noticed it. Why on earth would the previous owner put that junk in there? K&N filters have been shown in study-after-study to let more dirt into the engine vs. the standard HEPA filter. Also the oil gets onto the MAF sensor. Maybe that's another reason the engine sounds like it is on its last legs..... filled with dirt.
Question:
Do I have to do some kind of maintenance with the K&N? Or can I just leave it in there until the car dies in ~100,000 miles? Supposedly the filter cleans better as it ages.

[spets]

we don't have MAF sensors, we have MAP sensors. (pressure, not flow).

K&N filters should be oiled occasionally if you plan on keeping it in the car.

[biododge1]

I wouldnt worry about the K&N-or the thought that the car will be dead in 100K.(i have 300K on mine with one). Just get a "recharger kit" from a auto place like summit or jegs and do what the instructions say and all will be good.

[3-Wheeler]

Originally Posted by theaveng

.... Supposedly the filter cleans better as it ages.

I would oil the filter as has already been mentioned.

And yes, filters do tend to filter finer and finer particles as dirt accumulates on the surface of the media. BUT the accumulation of more media also tends to dry out the oil as well.

Jim.

[Cobb]

Ive run them and others I know with no problems. You should clean it if it looks dirty then let it dry, then oil it.

Oiling a dirty filter wont help flow that much.

I knock off the loose crap, use a tub in the sink with shampoo and soak it, then run clean water through it til it looks clean. Then place it in the sun to air dry. Then light coats of the oil spray so its a uniform red color and I let it sit for a few hours before driving.

I havent serviced mines in 66 thousand miles and it looks slightly dirty.

[Blue-Civic-Hybrid]

I've had a KN in my Insight since I got it, plus all my other cars over 18 years of driving, never had a problem in any of them.

Just oil it up twice a year or clean it once a year and you are good to go!

[theaveng]

The instructions say 50,000 miles but some people say they go 100,000 miles between K&N filter cleanings.

[Eli]

I would never subject a car that I wanted to last a long time to a K&N air filter. You may as well go to Home Depot and use a few layers of window screen as your air filter.

You can't have your cake and eat it too. If you have two filters with the same surface area, the one that flows more air will always also flow more dirt.

I prefer to keep dirt intrusion and therefor engine wear to a minimum, since better air flow doesn't increase fuel economy.

[theaveng]

(1) You shouldn't assume an engine will last 300,000 miles. I had two cars with identical engines. One lasted 360,000 miles but the second killed itself at just 80,000 since the seals were 25 years old and dried out. (2) My insight engine definitely has problems. It sounds like it has 300,000 miles instead of 140,000. It suffered severe wear under the last owner.

HEPA filters (the stock filter) do the best job for air cleaning and that's why the manufacturer put it there. K&N do the worst as these studies show. I'm getting that filter OUT as soon as possible and do an oil change to remove the dust the KN left through:

Aftermarket Air Intakes/Filters - Do They Work? - Diesel Place : Chevrolet and GMC Diesel Truck Forums

Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata
" I actually received an e-mail from K&N stating their filters filter within 99% of the OEM filters. This may be true, and 1% may not sound like much. I contend that 1% over many miles, may be important. Really, it is up to each individual to decide. The poorer flowing filters, remove more particles, and the better flowing filters remove less particles. If you think about it, that conclusion passes any and all common sense tests, so it is not surprising. "

[Blue-Civic-Hybrid]

That is a great link for the filter tests, but I'm still gonna stick with my KN filter.

My supercharged Civic has been running a KN for over 17 years, 11 of those years boosted and I have seen no ill side effects with over 210,000 miles of hard driving and racing events.

To each thier own...