Hi to everiibody,
I would like to tell you my story about K& N and may be save some MAF......
I have a CLK 430 since 2 years with 180.000Km now , 7 months ago I decided to put K&N filter because i was doing maintenance and i had to change MB filters.
Aftre installing these i was thinking to have more power in particular at low RPM but may be waspalcebo effect..........but after a while i had code P173 and p170 and car start tu run bad at idle and loose power at high RPM.
I tried to clen MAF with alcool and with special product to clean electronics, dry with soft compressed air..........but no result...
So i cnahged MAF and put new MB filters and the car i beck to normal.
This just to say you that for me this kind of filters are not working with car wich MAF like this.
I hope thse can save some owner to buy expensive MAF.
Many thanks guys.
Alberto

The K & N will kill any cars MAF..... many people are finding out the hard way.

The only gain you will get from using a K&N filter is intake noise, big waste of money.

When the oil dries out they no longer filter particles. Too much oil will bleed out and destroy the MAF.

The whole idea of a "washable air filter" makes about as much sense and "washing" your oil filter and reinstalling it!

Overpriced junk and a big scam! If K&N they gave me one of those turds, I'd throw it back at them.

Duke

Some manufacturers specifically mention that washable or oiled air filters will void warranty just for that reason.

On the flip side, some people reported these filters can work okay as long as they aren't over-oiled.

__________________
95 E320 Cabriolet, 169K

The MB Club website technical director posted a warning about K&N, of course some people got all bent out of shape. The over oiling distroys the sensor was part of the comments. If you want more speed get a bigger engine go AMG, "Renn Tech" , I toured their facility and did not see any K&N stuff

Alberto, I bet your MAF would've failed at the same day, same time anyway. Imo efi is a smog device, and the maf is the weakest link. I do not believe the K&N caused it to fail. There is no way that you or I can prove either way, but I had to throw in my 2cents.

Hey, I've been dying to take one these MAF sensors apart. If you would be willing to ship it to me I'd pay you the $5 or whatever shipping. I'll also post pix of the inside if anyone cares to see.

K&N is all hype. I have a Mustang I drag race and last time at the dyno we replaced the stock paper element with a K&N and got no HP increase!!!! Waste of thime and money.

Dan

__________________
81 240D 4speed with 300D engine
87 560SL
2005 E320
Yukon Denali
Sierra Denali
850 Turbo Volvo
1996 Mustang
1984 Mustang race car
3 Boats

but if you haven't seen this, read it with interest . . .

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

I have removed my K&N filters for good-old-paper!

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Greetings Jim,

Appreciate the link to this interesting whitepaper.

I want to share a maximum airflow formula to use when determining whether the air filter is really the bottleneck in your intake system. The background for this discussion is my previous experience tuning forced-induction V6 engines. Effective displacement of those engines was comparable to any respectable V8, and the tuning requirements arguably more complex.

Unfortunately most of my "black art" tuning models were developed using output from the MAF/MAP as measured by an OBD-II compatiable scanner. My 1995 E420 more or less leaves me "blind" to engine performance tuning at this point. One of the sacrifices I made by choosing a pre-1996 model Mercedes... anyhow, back to the formula:

(eng speed * displacement) / 3456 = xxxx cfm * VE

where units are standard, and VE is engine volumetric efficiency.

Let's use the 5.0L 119.974 as a working example:

The maximum engine speed for an unmodified 119.974 is 6000 RPM. Displacement is 4973 cubic cm, or 303.5 cubic inches. Maximum horsepower is measured at 5700 RPM, the stock full-throttle (WOT) shift point. Our question is whether the filter affects ability to reach peak engine output at the highest shift point.

(5700 * 303.5) / 3456 = 500.56 CFM

This figure represents the theoretical airflow through the engine without restriction and without accounting for thermal issues. The volumetric efficiency (VE) factor allows us to account for limiting factors (material, thermal, etc.). The M119 mostly suffers from underhood thermal issues, especially with an aluminum block that soaks up ambient heat.

If we use the common 85% VE factor, estimated airflow at 5700 RPM becomes 500.56 * 0.85, or 425.47 CFM. The 119.974 engine attempts to pull a maximum of 425 CFM through the filter and intake, assuming no underlying mechanical problems that would decrease peak airflow.

It seems to me that most stock (paper) filters are tested to flow at least that much air, if not more. My interpretation is that you will never encounter a need with an unmodified 119.974 to flow more air through the air filter than a stock paper element allows.

It also goes without saying that a comparable K&N product flowing 3000 CFM allows more dirt, oils, woodland creatures, etc. to pass through the filter than the paper filter. This has been demonstrated using empirical methods like those described in the whitepaper, and through basic oil analysis from engines where a free-flowing intake filter is used (higher silica content and other particulate matter). I wonder just how many performance engine failures are due to oil breakdown once too much airborne junk passes the filter barrier.

Agreed with Jim -- make mine a quality paper filter!
-DM

__________________
1995 E420 SE black/black
2004 Volvo V70R AWD

Funny my car runs better and accelerates better with the standard paper filter than it does with the K&N! I am talking about my 190E not my C class. The C class I would never put a K&N in due to the MAF and me not wanting to need to buy a new MAF for it!

__________________
~Jamie
_________________
2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....

I've had KE filters in my 400E for over 100K miles. No problems. Can't comment on before and after mileage but car does get 27 mpg in hot weather interstate driving at 70 mph. Car has 128K on it.

I've had a KE filter in my 944turbo track car for over 55K miles. No problems. I installed the MAF system 8 years ago. It came standard with the system.

This argument goes on and on and probably will never conclude. It's almost like an argument about religion. No one will have their mind changed....

BTW, I also use green antifreeze. My SL is 25 years old. The green stuff has not harmed it or allowed it to be harmed. But I do change antifreeze every 24 months.

__________________
Lawrence Coppari

2002 SLK32 AMG
2005 Acura TL
1987 328GTS
1986 944T

I was wondering if that article would show up. I'm sure it's correct, or close. If people want to say that a paper filter doesn't flow quite as well, but "good enough," then I say a K&N filter doesn't filter quite as well, but "good enough!"

DangerMouse:
It's not quite that simple... Even a carb/EFI mfg will tell you need more than the calculated # at 1.5" vacuum or you're screwing yourself. (We are talking 1.5 right?) A good 50% larger is a nice start
I bet the oem EFI on my little 320 is capable of flowing 4 times or more what your formula says. Shoot, even my 2.3 4cyl intake system is huge, the motor could never flow that much. I'm a fan of flow and all, but I wouldn't go that big.

benzfan:
I agree 100%, that's how Split Fire spark plugs made $$. Guaranteed to perform better! They never said guaranteed to be better than a new plug, because it can't.
One key factor for me on the K&N is that it still flows well when it's dirty. So keep your paper, just remember to change it constantly if you want those flow #'s.
I see a lot of dust in my truck and would need a new paper filter every 20 miles. Paper would start out with degraded performance from square one, but would go down hill quickly from there. My K&N always flows fine.

Am I the only one who has ever tried a K&N on a dyno? I read that ISO report and it just confirmed what I already know, keep a clean stock filter in your vehicle!

Dan

__________________
81 240D 4speed with 300D engine
87 560SL
2005 E320
Yukon Denali
Sierra Denali
850 Turbo Volvo
1996 Mustang
1984 Mustang race car
3 Boats

DangerMouse:
Yes, I have an open mind and absorb all performance car info like sponge (a lot leaks out, but I try).
The theory is nice, but real life is different. The flow #'s are based on 1.5" of vacuum, a normally aspirated engine does not draw that much, so all those # are based on an error. The 1.5” number is used because it’s easy to work with for testing cfm, much easier than say 0.1”. Vacuum means there’s a restriction, restriction means power loss. If you’re running vacuum at full throttle then you need a bigger carb, efi, filter or whatever.
Btw, a well designed smog engine may have 80% efficiency, but not a performance motor. Not that 80-100% is a huge difference, but 1.5” vs 0.1” is.
I don't agree with your forced induction and heat theory btw, I didn't make sense. Not insulting you, just doesn't make sense.


89-300ce:
Yes, I do run a prefilter, but again it was difficult to find one that didn’t kill flow and power. Mesh and typical foam like those used for dirt bikes are too restrictive; once again I found the solution from K&N. The prefilter is open foam, the cells are huge and flow nicely. I use regular K&N oil, not foam filter oil. It’s really amazing how well K&N filter oil works, The prefilter can literally be backed in oily sand, yet the cotton filter is 99% clean. I can only guess the cotton filters out 99% or more of that remaining 1%. Oiled cotton can catch smaller particles than any dry paper filter, just like an old oil bath setup.

mctwin2kman:
You need to tune your car to run with the increased airflow of a K&N.
I have a K&N in my 190E too, but it runs fine either way.