Hi I'm new here first time posting. I have a wicked concern and I know I'm overreacting but I just want to hear it from someone else... I bought a K and N air filter for my GX, long story short I found out the oil in the filter is bad for your car so I swapped it out with a Microguard paper filter that is identical to the OEM filter. The K and N was in there for no more than 5 days, could it have done anything?!

 

Some have complained that the oil in the filter ruins the mass air flow sensor. Of course KN disputes this as myth...other than the sustainable part of the reusable filter, it has no performance benefits in a stock street vehicle. No way that filter did anything in 5 days, let alone 5 years. If there is any truth to the theory it would be due to the user over oiling the filter after cleaning.

 

5 days? No worries.

 

I've used K&N Filters on my Mustangs for years..... in race applications only! For my cruisers and daily drivers I use the standard old Motorcraft paper element filter. There's no seat of the pants power gain advantage to a K&N for any stock application. I would imagine that 5 days isn't enough time to gum up your MAF. Maybe with a sloppy over oiled filter in middle of summer you'd have some build up. If you're concerned just remove the MAF and spray it down good with non-chlorinated brake cleaner, let it dry and then reinstall.

 

Unless you went out driving in the desert for those 5 days, you're fine.

I'd just switch back to the OEM filter. It's proven to work, and any HP gains (if any) by using an aftermarket filter will be minimal.

Chip H.

 

5 days I am sure your engine is fine. I don't mess that hocus pocus magic filter adding HP nonsense.

Stick with OEM, unless you are absolutely certain the filtration rate of this aftermarket filter is on par with the OEM filter. The OEM quality is very good and there is no reason to put anything else in your truck.

 

Thanks so much everyone!

 

K&N is a good filter. As long as you don't over oil it it won't hurt a thing. Even then its the MAF that is at risk. If it is a MAP sensor engine you have no worries. Once you have run the engine for a short time the over oiling issue is gone as well. The airflow will cause it to disappear and the engine and cat would burn it all away. It's a very thin oil. Nothing as thick as the oil in the engine that can also burn up in the engine. Your worried about nothing.

 

I agree. I run K&N because over the life of the vehicle, it comes out cheaper for me in the end to re-use the filter rather than have to keep buying paper filters. And the 300HP increase is nice too.

 

If your standards for what qualifies as a "good" filter is dirt filtration then K&N surely falls way short of OEM and other aftermarket filters. In fact according to ISO tests it generally performs very poorly when it comes to dirt filtration.


Debunking the K&N Myth – Why OEM is Better

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

Air Filter Test

http://www.billswebspace.com/AirFilterTest.htm

 

Good, not Geat, not excellent. Filters for performance are not as good at filtering dirt. They make a prefilter as well. I am not recommending them. I don't run them in any of my vehicles now. But the OP was worried that he had ruined his engine because of the oil or some such thing. That's just simply is not the case. The previous posters didn't seem to understand that the oil is not hurting anything if his car is fine after the first day of driving around. You would need to severely over oil the filter for that to happen. When I built track cars that all used MAFS I never heard of a single car damaged as a result of a over oiled filter. The internet has a way over overblowing things big time.

 

K&N are good on race vehicles because they need the extra airflow, don't really get driven all that much (not commuter vehicles), and the engines get rebuilds a lot more often than a typical car.

IMO, use them on the track, but don't use them on a daily driver.

Chip H.

 

the hotwire mafs that are in our cars are not ruined by the oil on the filters. People say that due to older cars that had "karman" maf's like the 92-95 sc300 and sc400's where if you use an oiled filter it will ruin those mafs.

a hotwire maf like our car has though, you can just spray some maf cleaner on it and it will be good as new again even if you had oiled it up from a K&N filter. it will not ruin it, so no need to worry.

Beware of blanket statements like oil will ruin a maf, it only ruins the mafs they used in the early 90's, and does not apply to your gx470. I run the spectre filter it allows more air and isn't all oiled up, and half the price. really works well with the catback exhaust I can tell its got a much snappier throttle response and feels more powerful than my other stock GX. They are fine for daily drivers but if you drive through dust storms or a desert or something, put the stock filter back in seriously.

 

K&N and others make what's called a dry filter too, which is a logically option next time. Nothing happened in 5 days so you have nothing to worry about. The fact is on most vehicles even Lexus the PCV valve where the pressure and excess oil goes out of back off a valve cover is then re-routed in a hose back to the intake just past the mass air flow sensor to the idea of that excess oil will be burned off on the combustion charge when it goes back in.

This is why Turbo guys use a catch can to "trap" the oil from A. Going out all over the engine bay and environment and B. Keep the air fuel ratios legit without oil getting in the way again.

The type of oil used on a K&N filter is so minute that it would not really matter except for in some rare cases as stated above that could effect some types of mass air flow sensor filaments.

Sorry for the long explanation but in short just use a dry filter so you dont have the concern.