K&N air filters ruined my engine

[henryburrows]

I recently decided to replace the OEM filters with K&N's in my stock intake boxes. I've used K&N's in my vehicles before without problems and my M5 has around 40,000 miles so I saw no reason for hesitation for a fresh set. At around 100 miles after the install the yellow engine light came on for the first time since I've owned the car. I've never had any engine issues and she's always run like an absolute champ. I took it to the dealer and immediately they pull the MAF's which are clogged up with oil from the new K&N filters. They replace the MAF's, clean the intake pipes and put back OEM filters which set me back a hefty penny. Things were good for around 5 minutes after leaving the lot and the yellow light finds its way back on. Back to the dealer... They pull the spark plugs which also fell victim as a result of the filter swap. Around $1,800 later I pull off the lot again. Things are fine for a week or so until I drop to 2nd on a freeway onramp, rev to around 4,500rpm and this horrible farting noise comes from the exhaust, engine cuts power to limited mode. I'm now sitting here writing this with my car at the dealership overnight and very worried for the integrity of my engine as a result of a pair of air filters. Has anyone else had to resolve a dispute with an aftermarket part company?

[WickedBMW]

I have a pair in right now. It seem they perform like they should. Thanks to your post I’m might order afe pro dry filters

[YanoM5]

When I had my K&N intakes I’d get a couple lean codes, thinking it was O2’s going bad. So I’d reset the code but it would always come back after a few hundred miles. After doing more research I found out it could be my MAF due to the oil from the filters. Sure enough it was. I used MAF cleaner to clean the MAF’s. They were so drenched in oil. After doing that and blotting the filters no more check engine light.

[Craze]

Never use oiled filters in maf cars
I know many can but the bmw are very sensitive

Use afe dry filter or eventuri intakes
They are tested to filter better than factory eventuri

Im sure the car is fine but id replace the mafs

[henryburrows]

Dry air filters seem to be the only way to go. The fact that they would sell these specifically for F10 M5 drenched in oil should be something they should address. Unfortunately, I'm not savvy enough to have predicted they would gum up the electronics.

[josec70]

Been running K&N's for two years w/ zero issues.

[Chauncey.Bishop]

As mentioned earlier, you should always use dry filters in your car for safety. Many of us resist using oiled filters to avoid the same outcome you currently have. That being said, you could have easily sprayed MAF cleaner (instead of replacing the MAF), cleaned the intake pipes and changed your sparkplugs yourself without having to spend so much at the dealer. It seems like they're taking full advantage of you by throwing parts at the problem rather than doing a proper diagnosis.

[Pikey Motorsports]

I doubt they have ruined your engine

[boots]

Ive had my filters after two weeks of ownership Dec 2013. Never had a issue

[MMMMM5USA]

I put the K&N on my M5 f10 and experienced the same issues, removed after 100 miles and found oil in the right intake. Just cleaned the filter and MAF with spray and put the original filters back in...Left the aFe scoops and all is fine. Parts guy refunded my money for the filters but now my engine light came on but I think it is due to the oil change that I have to get done, car runs fine. The same issue happened to me on my X5, never again will I put performance filters that have oil

[MMMMM5USA]

The oil would never make it to your spark plugs, at least this is what I have been told, so not sure why they would have told you that, hope all is fine which I am sure it will be

[MIM5]

I have k&n filters that I haven’t put in yet, and was wondering would they work fine if cleaned and didn’t oil? I know other brands like AFE have dry filters, but would cleaned K&N’s work the same as those other brands?

[JMD]

Just a question,...perhaps there was too much oil applied to the filters? I've had a K&N filter in a previously owned 535is,...of which,....I cleaned/oiled the filter on two different occasions,...let sit a while (...about 5-10 minutes) before reinstalling and had "zero" issues with the car.

Now, an '88 535is is not an F10 M5,...so, to top that, I recently took my 2012 X5M in for service,....and my SA said it needed new air filters. So, they replaced the air filters,...I go to pick up the X5M,...the dealer SA says, "we replaced the air filters and placed the K&N filters in the storage area". The surprise here is that I had been driving it for about a year and just discovered that it had K&N aftermarket air filters. Had I known this,...I would have simply cleaned and re-oil them and re-install. I'm glad they didn't throw them away.

So, there is a good chance that your K&N filters had way to much oil applied!

[YanoM5]

Based on the comments it looks like some filters may have too much oil or possibly due to weather it doesn't absorb the oil as much. Funny thing is patted my filters down with a paper towel, but it still caused my MAF's to act all crazy.

[apexlocator]

I recently had to clean and re-oil my front mount k&n filters (RK autowerks intakes). The recharge kit I bought last year finally finished up and was able to re-oil one filter. The new recharge kit oil I used on the other filter leaks the oil after a couple days....I mean, one filter (older recharge kit) is fine, the other filter (newer recharge kit) sat in a pool of oil.....same application and same part # on Amazon.

I wonder if k&n changed their oil...

[MMMMM5USA]

Since my situation was from New K&N filters you would think coming from the factory the oil would be applied automatically and evenly...personally I would not use oiled filters again and especially with MAF sensors...a good cleaning with MAF spray and you should be fine...cannot believe it would ruin your motor

[steeve13m]

Originally Posted by MMMMM5USA

Since my situation was from New K&N filters you would think coming from the factory the oil would be applied automatically and evenly...personally I would not use oiled filters again and especially with MAF sensors...a good cleaning with MAF spray and you should be fine...cannot believe it would ruin your motor

Yes K&N is known to affect MAF sensors....as mentioned the trick is to clean the MAF with CRC MAF cleaner at every oil change and you will be fine.....AFE DRYflow works but does not flow as well as K&N

[Larry77]

I know this is an old thread but I have recently been looking into a new drop in filter and noticed that neither Turner or ECS sells the K&N filters for the F10 M5, maybe there has been too many issues (would be odd for them both to drop their dealer status wouldn't it)? They do sell the K&N cleaning kits though.

[BeachM5nster]

Originally Posted by henryburrows

I recently decided to replace the OEM filters with K&N's in my stock intake boxes. I've used K&N's in my vehicles before without problems and my M5 has around 40,000 miles so I saw no reason for hesitation for a fresh set. At around 100 miles after the install the yellow engine

Sucks this happened BUT when i got my M5, first thing i learned on here was to avoid K&N / oiled filters..

REASON being: the S63 is a beast and will suck the oil right out of those stupid things.
ALSO the OEM airbox is as good as any intake for a number of reasons.
but go ahead and get the front mount intakes that will invite a rock into your motor. lol.

but honestly, the premise of an oiled filter is retarded. its only purpose is sO iT cAn Be WaShEd and UsEd FoR a LiFeTiMe.,

man, just buy a brand new dry filter every now and then.


STORY TIME:

back in 2002 when i was a teenager i had a new Lexus is300, i thought i was gonna be hell on wheels with a turbo bolt-on but little did we know Lexus was aiming at being lame practical but dependable seeking the 50+ demographic.. which theyve accomplished and have become the boring company they are today.
they locked the ECU so good its still not decoded and they made the 2jz unfit for boosting but made to last a million miles without boost ZZZZZzzzzzz

well anyway i got an injen intake with a K&N cone filter and that thing FOOOKED my MAF.
i cleaned it like 1 other guy suggested here, but its a sensitive little sensor. it was foooked.
had to get a new MAF at the tone of $400 in 2003 and i was a teenager.
punch to the gut!

Now if you live in the Congo, and you have no way of getting new clean air filters then sure maybe the KN air filter is a good idea. But I hope you have, or keep the bottle of cleaning oil with you.. so on second thought

KN air filters just make no sense and serve no real purpose

other than being a real old man that thinks having one airfilter for a lifetime is a bragging point or something

[MIM5]

I’ve always used k&n filters with no problem. When I cleaned and re-oil I’d let it sit for an hour or so to absorb, and then blow compressed air through then until there’s no residue coming off. Usually lay it on paper towel at the end so that when I’m blowing air through them I can see if there’s the slightest bit of oil that comes out.

[M5Rick]

No KN oil filters on F10 TT's.Those intake pipes are like a powerful vacuum cleaner ones and on full boost will suck the oil onto the maf's in no time.

[NotSooFast]

Whatever he ^^^ said.

BMWs are known to be sensitive to oiled filters. If you want to splurge $$$ go with the Eventuri or AFE drop in dry ones.

re: cleaning off the oil - it is this oil which does the filtering leaving the filter to have larger pores (as compared to non-oiled ones). AFAIK - removing the oil may lead to more harm in the long-run.