DogDinner

Howdy folks, long time no post!
Just had a call from the MB Dealer back home, and he is telling me that the MAF needs to be replaced ( have already ordered same, (Thru BuyMB parts, which happened to save me a nice 800 smacks, as always, love doing business with those guys), service is telling me that I need to replace the K&N filters with OEM because the oil from K&N damages the MAF. Now, I have had K&N's in my cars and trucks for the better part of 15 years, and I have never heard this.....any comments?
TIA
Frank

CDP

Recently, my MAF unit on my 1995 E420 went bad and I had K&N Filters running at the time and I made sure the filters were never oiled more than they came from Factory.

Now I can't exactly say the K&N's are at fault since the MAF unit has never been replaced before and it looked like an original part on the car since day one.

However, before I replaced it I did use some MAF sensor cleaner and the MAF did temporarily worked again so that leads me to thing the K&N's werent at fault and I do know of many AMG owners who use K&N's and don't have problems at all. :dunno: :hmm:

I will probably run K&N's again when I change my filters since I never had a problem with them on my 1990 300E.

E3002.8

I know being a VW tech that we dont support k&n filters cause the oil will take out Turbo's over time. not overly sure but i can understand how it might be possible to take out maf's.

C43AMG

Look here for K&N's statement about MAS's & their filters : http://www.knfilters.com/MAF/massair.htm

ZedStyle

they make millions of these things, i personally think it's very possible that every now and then there's a manufacturing defect like too much oil or something on the filter that gets past the QC people and causes an issue like this one... K&N can run tests all day, but if they're not running tests on a defective filter, then obviously the results will be positive. Odds are you will never get a 'bad' filter (if such a thing even exists - my opinion), but I stopped using them myself. Good luck with getting the car fixed!

childofjuly

Check out this link on K6JRF (Jim)'s Mercedes page.. its for the M119 but he has some pretty interesting information on the topic. cheers!

ZedStyle

great post!

2PHAST

If you over oil or oil the wrong side of the filter, it is possible to oil up the MAF sensor, that is where this whole "K&N filters will destroy your MAF" story originates from.

I to have used K&N's for well over 15 years without issue, further more, I have done my own tests that confirm what I state in the first paragraph. A good MAF cleaning will normally restore a MAF that has been coated with oil.

Also, do remember that MAF's do wear out (the sensor) and at some point, they no longer will function correctly and no amount of cleaning will resotre them to full functionality.

Dealers replace these all the time, a simple voltage test via the SDS will determine if they are within specifications, if not, a new MAF is installed.

oneill_1

had this exact problem with my car...it was a pretty penny too to replace.

-OG

Quicksilver500

I spoke in length with the K & N guys at SEMA about this last year, they showed me a video where they use a air brush to spray their oil on a number of MAF sensors and it doesn't damage it. They said if you think their filter has damaged your car to call them and send them your MAF and they will send it to a third party lab (I think Blackstone?). They said majority of the failures are do to dust and oil/glue from the air mass messing up the film on the sensor. I think you are actually safer with a K & N because you never have to worry about the sensor going out because of a dirty filter. A dirty filter will kill one faster than anything I know, also the more you use it, and after everytime you clean it it becomes more fibrous so filtering actually improves (this is what the engineer told me from their tests, and it makes sense). I just got tired of changing paper filters all the time in my cars and I have been very satisfied with K&N.
-Mike

2PHAST

No need to purchase a entire MAF, the MAF insert can be purchased for about $100 off of Ebay (original Bosch part). Although you need a special 5 sided security torx (not six) to remove it.

I run a M113 MAF on my M112 motor, but I use the M112 insert in the M113 MAF assembly (the M113 MAF is larger and flows more air)