Just wondering....is it possible that using an oiled air filter such as K&N could contribute to "coking" on the intake valves on a direct injected engine? Just a random thought...

 

Only if you over oil and don't follow K&N's instructions. The MAF already gets some oil from the PCV system on nearly all cars and they don't seem to have major issues.

 

Agreed I would think you'd have to have the k&n just dripping oil for it to be a problem.

 

No, it really doesn't and you shouldn't make things up.

The PCV doesn't go the air inlet at all. The PCV goes from the valve directly to the intake manifold well downstream of the Mass Airflow Sensor (MAF).

Maybe I should assume you actually meant the breather hose that goes to the intake air tube. No, it doesn't oil the MAF either. It is well downstream of the MAF sensor as well.

Oil contamination is a very real issue with filter that use it. It can cause some strange and sometimes hard to diagnose behaviour.

 

Like I originally posted, just a random thought....have used them on some previous cars no problem, but none of them were direct injection....just wondering 😀

 

You have no worries about using a K&N filter on your DI engine.

That being said the K&N filter is got to be the lowest bang for the buck thing that one can do. Just my .02, but it's pure hype. Use them if you like, but don't expect much.

 

I don't expect much of anything, these days

 

Totally agree. Only did it because I got it on sale and after 2 regular paper filter replacements it would pay for itself haha. After I put it in, I didn't feel much difference nor any noticeable MPG increase.

 

...except more dirt in your engine.

 

I have personally used K&N air filters on my 2000 Civic Si for 167K and my 2015 Civic Si with 84K with ZERO issues. There really is zero evidence that it's even a problem so, no it isn't a very real issue.

https://www.knfilters.com/MAF/massair.htm

 

The 2000 civic doesn't have a MAF sensor. You could spray oil into the air intake and it wouldn't mess with the sensor beyond what fuel the oil added.

As long as they are not excessively oiled they do what they are designed to do. But many people do over oil the KN filters and it DOES cause issues. I wouldn't say to not use one or to go out and buy one. Just make to sure to not over oil if you do use them.

 

I don't over oil mine at all but did you read the link I posted? No one has submitted credible evidence to K&N that this is an issue. It's dealerships making stuff up so they don't have to pay warranty.

 

Fuelish, interesting idea on the K&N with DI. My thought is that the quantity of oil possible is nothing compared to the oil dumping that these improperly designed PCV systems are causing. The pictures of these Honda, VW, BMW, etc intake valves are disturbing! VW is fighting the issue with revised PCV systems. Ford is adding a second set of injectors. Not sure what Honda is doing.

Bought my first K&N in 1988. Ran my first one on a MAF equipped vehicle in 1989. Had one on every car since and I'm a high mile driver. Have put over 200,000 miles on multiple vehicles.

No issues, but I don't over oil them and I don't expect any real performance gain. Just the ease of not buying filters and the, possibly, reduced operating cost over the vehicle ownership period.

Just bought a new filter for the Fit though. Darn mice built a nest of home insulation in the airbox. That stuff does not want to come out of the metal pleats! Bought a dry gauze filter to try this time because I found it "cheap."

 

yah, i was like his car is having oil reflux or something..

 

maybe not on your honda, but ive seen people's MAF get oiled from K&N cai's on 370Z's. so it not dealers making shitt up.

 

So I'll start out with,, I didn't make it up.. so you can suck it..

Take any engine with a few miles apart,, (Not just a Honda) there is always oil residue in the intake all the way to the filter. (Intake reversion) What do you think collects on the valves in the DI motors? Its OIL.. I have 3 vehicles all with K&N filters, (With wraps) and 2 of them have MAF's one is MAP only (My GD)
Between the 3 I have 650 K miles and no issues, sold several others with 200K plus, I'd guess I have about 2.5 million miles on K&N and never found a problem ,,, .. The dealers DON'T like you not paying their blood sucking parasite money for their filters.

 

Wow so much anger in this seemingly friendly K&N thread.

A dealer can say what they like. Sir that fancy oiled filter screwed up your fuel injection system, please pay the cashier $1500. Of course the filter didn't cause this, but a dealer sure could say this.

Back on topic oiled filters that can go one MILLION miles.

 

A CAI such as K&N is just a free flow filter. Paper filters restrict air flow a tad bit because they are so dense to catch dust where the free flows use oil that dust "sticks" to in order to catch and clean the air. Engines breathe better with the free flow as motors are an "air pump" the more air that gets in the more that goes out as to why some also install larger exhaust pipes, throttle bodies...ect.... same as when adding a turbo, need bigger pies to get that air out otherwise theres nowhere for it to go and crates extreme back pressures.

 

CAI stands for cold air intake and it is a bit more involved than just a free flowing filter. wat you're referring to are wat we call K&N drop ins. as in drop in replacement filter.

 

Yeah, perhaps I should've specified "drop in" filters...