RES

When I purchased my Kleemann kit it included a K&N filter. I installed the kit and continued to track my mileage. I track my mileage by recording the dates and gallons and trip meter miles each time I get gas. This I learned years ago can warn you of problems before they become big problems. It usually means something is wrong if the mileage drastically goes down. At first the mileage was not that big of a difference. The trusty computer was saying great mileage but the numbers where coming out low. So after a few miles on the kit, it started to drop drastically. Before I was able to get between 400 and 425 miles per tank, now I was down to around 325 a tank. I started to think of all the things it could be. I had replaced the spark plugs recently and the filter was kind of new. There is the MAF, MAP, and oxygen sensor that help schedule fuel. What could it be?? So I decided to remove the air box and inspect the first two. What I found was an oily mess in the whole intake. A film covered most of the inside of the pipes and the MAF sensor to. I had this same experience in the past and pulled the filter out completely. I thought it was from cleaning and over lubing the filter but this had come straight out of the factory rapper. I had to thoroughly clean the MAF and all the pipes on the intake and I replace the filter with a Mercedes filter. Now my fuel economy is back up and all is well. I have looked into some of the other filter, like the green filters and might try those. I’m looking for any feed back on those. But for now I would recommend staying clear of the K&N filters so you don’t experience the same problems. A side note when we did before, and after dyno’s with the Porsche 928’s, the results showed a 6HP drop when compared to a stock filter. I hope this helps other when considering a filter change.

advans

wow.... now im gettin worried with my k&n filter, might drop the stock one back and see how it works

j_belll

same here, but i like my K&N!

tee_tz

Hmm, that's interesting. Well glad I didn't install one.

I couldn't imagine it giving much of a gain in any case.


Tee_Tz.

splinter

Yes, it does.

Mercedes has equipped their vehicles with excellent air filtration systems as delivered. They are designed and built with generous flow capacity and CAI. When visually comparing K&N (and Green) filters against the OEM filters, (Mann, Knecht & Mahle) it is readily apparent that the aftermarket filters are not built with the same regard to their primary function: filtration. The stock filters have far more (and taller) pleats. They also tend to fit and seal in the airbox better. The purpose of the pleats (in any filter) is to increase filtration surface area, and improve debris holding capacity before any significant restriction occurs. The original filters also provide much better filtration, to a far smaller micron rating, than the “high performance” aftermarket offerings. http://bobistheoilguy.com/airfilter/airtest1.htm

The days of quick, cheap, and easy horsepower increases are long past with the German marques. Not too long ago, during my Camaro/Corvette phase, verifiable (dragstrip) improvements were oh so easy to achieve. The Asian brand tuners still do very well retrofitting decent intakes for their customers. We already have one, stock. For as willing as I am to invest honest dollars to help make my MB get down the road ahead of the next guy, the anticipated gains from air filters are simply not there. However, the potential disadvantages are real, and not to be discounted. Pullies, cams, headers, supercharger porting, and competent ECU tuning are our only true avenues towards more bolt-on power. Alas, none of the respected tuners are exactly giving those goodies away.

Thank you, Mr. Stevens, for your enlightening post.

SeaCoupe

I guess I'm going to be one of the lone guys who is Pro K&N.

No worries, I can take the heat.

For the record, I do not have any of that oily residue that is referenced.

E

AdamVax

well thats good to know i almost bought one many times before but never did......what do you guys think about the BMC Air Filters? iv heard good things about these filters http://www.bmcairfilter.com/VisDetail.asp?ID=401

Harry Madan

Ya, i found this out about 6 months ago and posted an article on this form but it just seems to have disappeared.

That is the reason that i switched to Green air filters, and i really like them after seeing there demonstration at the dealer and comparing it with others i was really impressed.

newton22

I just put in K&Ns last week. No difference on the butt dyno. Not that I was expecting power gains, but I wanted at least a small improvement in throttle response.

Out of paranoia regarding the oil, I did let the filters sit uncovered in the living overnight before installing them. I'll run them for a few months and see how I like them.

AndySays

The BEST filter you can possibly get is the filter that originally came with the car, the stock paper filters. Down the road when you (K&N users or any other filter that needs to be prep with oil) end up having to replace those MAF sensors under warranty, don't be surprise that if the dealership voids your warranty. The source of the problem is those aftermarket air filters with oil that is causing you to replace the oily MAF sensors Luckily there was a thread posted on this before I decided to buy some K&N's

BabyBenz6spd

I've had K&N filter for almost 60k miles, I haven't experienced any negative effects.

WaveyKat

thats bad real bad i had a set of K&N waiting to be installed Oh well Stock filter i will be keeping mines.

drexappeal

Russell, thanks so much for the post. I guess I'll be changing back to OEM ASAP (glad I kept it). My gas mileage has definitely gone to crap (especially with all the current mods).

nlpamg

sheeeeit. looks like I'll be going back to stock. this is horrible to hear. thanks for posting it man!

cla 1000

I just got 23 miles per galon driving mostly in the city, and just about 50 miles on that tank of gas were done on the freeway. I have Green. Never dynoed but I like my green. Never had any problems so far. I have about 20k miles with the filter now.

14cue

^^^ i'm switching back too! doh, no OEM air filter...
does any one happen to have the part # for the C55 air filter?

AndySays

Ok guys, I took the time to find that thread I mentioned earlier why I'm never gonna use pre-oiled air filters. Made a search and found it in the 178th thread listed (some might think I'm crazy for searching this much but I'm not gonna fork over money for some repair work )

Look for Buellwinkle's post #4
https://mbworld.org/forums/showthrea...ght=air+filter

chriz4

Hi guys,

I'm from Singapore & drive a C180 Komp Sports Edt.

Changed to K&N for abt 2wks already and my exhaust sounded louder, sportier and bassy. I'm concerned abt what i read here so i put back in my stock filter. Now it sounds normal again. "No kick".

Think i'll email to K&N in US abt this issue for their comments.

Did this problem affect many Merc K&N users?

BKLYN_C

Had my K&N for 2 years. No problems at all. There is no oir resedue discribed above and the actual milege is slightly better than it was with the OEM

chriz4

Checkout this message from K&N. Useful, detailed info.
http://www.knfilters.com/MAF/massair.htm

Makes me respect them more. My K&N is going back into my car .

RES

They can claim whatever they want and you can choose to believe what you want. I am not a dealer or did I recommend any filter options. I simply had a problem and thought I would pass this information onto fellow members. This is the second car I had problems with so even after the first one I gave K&N a second chance. To see such a dramatic change after I cleaned everything tells me that I found the cause of the problem. The MAF elements are very sensitive and it only takes a slight bit of contamination to effect its function. What I found in my car was more then enough to cause a major problem. The element heats up when it operates so if you add even the smallest amount of oil to a heated surface what happens? You get a burnt brown surface and the element will not get a true reading. Simply spraying cleaner across the element it returned to its shinny self. So if you can think of any other source of this contamination I’m more then willing to listen to other points of view???

c230K415

Thanks for your review Russell. I actually popped in a drop-in K&N on my Lexus Rx300...ever since I popped it in I felt my whole car just "bog down" if you get what I mean. I checked the MAF and everything...all clean but just looking at this filter and how greasy it is (probably greasier than a extra crunchy piece of chicken breast from KFC) makes me think this is the whole power loss feel with my car. I thought it was just me and the car is getting old...but I put in that K&N about 5,000 miles ago...and I alwas already feeling the bog down affects after running 2,000 miles with it.

Maybe some people get a really greasy filter and some don't...however I did let my filter air out for 2 nights prior to putting it in my car. Hmm...who knows. If anything, just to avoid problems, I will just replace with OEM filters.

themerc

I appreciate you sharing this experience.
After 5 years and several different Audi, BMW, and MB cars - trying various aftermarket air filters (K&N, BMC, Green, ITG, Dinan); and searching and reading many threads of other's experience, opinions, and tests;
I like best to simply use stock air filters, and change them more frequently than the factory recommended services.

Many folks have had no problems with aftermarket air filters, but I have yet to read of a fouled MAF (and the related performance issues) from someone who used OE air filters and replaced them in reasonable timeframes.

Harry Madan

Just another side note;
The K&N filters do let dist partials through, and when changing your oil u can notice them dust that the car has collected.
I have now been using Green filters, and they are not an oil based filer. its is a full cotton filter and for the last 20,000K that i have been driving with the Greens i my gas economy has not changed much from the factory filter. I will try to find the full article on how the Green work. But what i do know is un-like the K&N the Green filters do need to be cleaned i think every 30,000K where the K&N does not need cleaning till like 100,000K.. the tests for K&N have shown that the dirtier the filter the better it works, that is why K&N add says that you wont need to replace you filter for the life of your car

"Russell Stevens" you should really try out the Green, i really like them. After i saw the in store display at the shop on how they work, i was truly impressed the test consist of:
they had a K&N filter display and a green filter display side by side so i could compare. and i know all of us here have seen these displays, where there is a filter and a fan behind the filter and when u turn on the fan the little ball in the tube floats to the top of the tube. Ok so the test that the sales man mad me do was put my hand over the K&N filter and see what happens to the ball, when i did that the air flow reduced and the ball in the tube dropped more then half way down, then he had me do the same thing with the Green and i was amazed that the ball never moved it stayed at the top the whole time.

C230 Sport Coup

I'm certain this has been covered many times before...
Anyway, yeh, if you do put an oil based filter, be sure to take it out when going for service under warranty.
For the Kompressor models, it just makes such a huge mess, since the air
flows through the intercooler, MAF etc.
Just don't do it.
Luckily I got mine completely cleaned out under warranty, well actually, they charged me 100 bucks, and called Goodwill, since they said they pulled all the
intercooler piping etc. but it's actually a covered item.
I'm back to stock and staying there.
No more blown MAF's.