Fiber and oil residue from the K&N filters will clump up on the hot wire in the MAF sensor. Ford put out several bulletins concerning this problem. Even the stock OEM filter lets enough debri pass through eventually so the hot wire gets an insulating coat and therefore gives an improper reading.

I use a lintless linen cloth and electrical contact cleaner to GENTLY wipe them down.

The problem with oiled filters and new "hot wire" electronic MAF sensors is this... oil from the filter migrates onto the hot wire filament on the MAF. The oil then creates a hot spot on the filament, which causes the filament to burn and read improperly or fail completely. This is the same thing that happens when you get fingerprint oils on the quartz envelope of a halogen lamp.

VW TDI MAFs are similar to the new Mercedes MAFs, and neither likes oiled foam or oiled cotton gauze filters.

99.99% Isopropyl Alcohol also works very well to clean a MAF sensor. Fill a Zip-Loc bag half way, insert MAF, swish gently, remove and allow to dry.

So what were the old style MAF units that didn't seem to have a problem with it?

Would this new sensor allow us to run the K&N without a problem?

Mass Air Flow Sensor alternative

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Digging up old corpses...its late in the night and I felt like hating K&N

Ha ha ha....a good one to bring back to life.

Here's my favorite from Mr. McClure:

After the experience of several Ford lemon projects, that name-dropping says it all.

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79 300SD - $50 out of pocket purchase
03 Dodge Ram 3500 CTD
2003 VW Jetta TDI

I think that this cotton gauze filter hating has got a bit out of hand. About the only valid issue with them is the fact that they can cause problems with MAFs (which most of our diesels don't have). No, you won't make your car into a tire melter (or even gain much power at all), but they are not going to destroy the engine, even if it is run longer than 8 seconds. I have 60k miles on my ford with a cotton gauze filter with no problems (and it does have a MAF sensor) and one on my MB diesel as well.

Unfortunately the test link is dead, but here is another link for your reading pleasure. http://www.thedieselstop.com/contents/getitems.php3?K%26N%20Letter%20to%20The%20Editor

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Any filter that I can see through is junk in my book. I'm not going to rely on a thin layer of oil to do a job the filter itself should be doing.

Mine does. However, I just take the screws off and spray off the MAF every so often as a PM.

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Facts do not change.

K&N is TRASH for MB diesel engines...

There are many MB owners with 300,000 or more miles on their vehicles due to good MB engineering and proper filtration.

K&N started out, IIRC, as racing filters on dirt tracks.

For that, nothing beats them, as you can hose off the dust (or mud!) and re-oil in a few seconds and be back on the track.

The only way to get adequate filtering with an open cell foam oiled filter is to put enough oil on it, and that means oil will blow off of it onto the filaments of the mass air flow sensor (and everyone is using heated platinum wire ones these days), and it burns on or insulates the wire, causing mixture and hence drivability problems.

No one seems to remember that the ONLY time the air filter has any effect on air flow is when the throttle is wide open at high rpm-- and how often can you drive with the throttle wide open at high rpm?

The K&N does, however, SOUND much more aggressive, since there is no muffling of intake noise....

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

As a said before, not to mention the fact that most of our engines are turbo charged. A turbo will suck air through a horrible looking filter, you would be amazed at how dirty a stock filter has to get before you can record a difference in the 0-60 times.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Anybody have any links for other effiency tests for these types of filters that support or counter the data by K & N?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

How long do dirt track racing engines last between teardowns?

How long between oil changes?


I've seen small hp increases aspirated engines, turbo diesel engines doesn't seem to make a difference. But, marketing works and ppl are willing to drop down $40 on a filter instead of getting a stock german one. I've seen on newer cars lots of dead MAF's which are linked to these "high-performance" airfilters.

I'm not dirt track racking and did you see recently the taxi driver that turned his 77 240d in at 4,600,000 km. If I could get 1/3 of those miles on one car- I'd be set for life.


Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

Great point.

240D with 4.6 million kilometres on the clock
http://www.peachparts.com/shopforum/diesel-discussion/115725-240d-4-6-million-kilometres-clock.html#post821427

Even though a new K & N might (notice I said might) work effectively, you had better be very careful and meticulous in cleaning. It does not take much to mess it up.

I would not run one personally. I'm running an Amsoil foam filter on my Powerstroke and never had a problem. Not one bit of dust in the intake tube, and I live on a dirt road.
The Benz has a stock filter..