K+N Filters are a bad idea for diesel engines.

[whunter]

The K&N filter issue has been covered many times, and in depth.

My 300SD... Aaron says its "destoyed" (chrome wheels)
http://www.peachparts.com/shopforum/mercedes-benz-wheels-tires/117835-my-300sd-aaron-says-its-destoyed-chrome-wheels.html#post840084

K&N Filter Efficiency Tests
K&N Filter Efficiency Tests

K&N for the OM603
http://www.peachparts.com/shopforum/diesel-discussion/104986-k-n-om603.html#post721322

K+N Filters - for a Diesel ??
http://www.peachparts.com/shopforum/diesel-discussion/103562-k-n-filters-diesel.html#post710523

Air Intake Mod....
http://www.peachparts.com/shopforum/diesel-discussion/63464-air-intake-mod-post984631.html?posted=1#post984631

[H-townbenzoboy]

In the words of Homer Simpson, "That's what I've been trying to TELL you!" Thanks for the valuable links. I knew I was correct in my assumptions.

[Hatterasguy]

Yep waste of money for these cars at least.

[oldnavy]

Funny thing about most of the people on the Magnum forum that use the K&N filters, they don't plan on owning the car long time. Most are probably trading cars every 2 to 4 years and are not concerned about possible engine damage, it about the "sound" of proformance.

[dunl]

They're bad for any engine....they let it too much dirt.

If you use one, put a paper filter behind it and se how much dirt it catches that the K&N didn't.

[Matt SD300]

Yep, Just hold one up to the light...........See for yourself.

Lots of holes in the filter for dirt to come thru!!!!!!!!!!!!!!!!!!!

[invol]

If the K&N filters are as bad as people say they are, is there any kind of alternative? Eventually, I would like to remove the airbox and use something smaller (i.e. cone-style or equivilent size). I'm not wanting to do it for the extra 0.082145 HP, but rather for the extra room it would afford me for another project. Seeing as 190s are not well-endowed in the "wide open engine spaces" department, every little bit of extra breathing room I can get will definately help me out.

Any suggestions?

[wols0003]

I'm going to defend K&N a little bit here from the typical bashing they often recieve on forums. Why don't you put a secondary filter behind a paper filter or the OEM filter and look at the copious amount of dirt it collects. Dirt gets past any filter. If you don't believe me check out this link. http://www.bobistheoilguy.com/airfilter/airtest3.htm

Yes, K&N filters let in slightly more dirt than an OEM; I should say very, very slightly. It won't make any diference to the oil or the motor. Oil is designed to deal with a certain amount of dirt, and using a K&N filter is not going to bring the oil over the dirt-threshold point.

Just look at the secondary filter in the tests with a paper filter; it's filthy with dirt. Just think about all the dirt that is getting into your engine with your oem filter. Surely your engine can't survive with all that dirt grinding around in the engine can it? Tired of K&N bashing...

[Pete Burton]

Originally Posted by oldnavy

Funny thing about most of the people on the Magnum forum that use the K&N filters, they don't plan on owning the car long time. Most are probably trading cars every 2 to 4 years and are not concerned about possible engine damage, it about the "sound" of proformance.

My sentiments exactly - which is why I would never buy a vehicle that is pimped - unless it was for parts.

[oldnavy]

Originally Posted by wols0003

I'm going to defend K&N a little bit here from the typical bashing they often recieve on forums. Why don't you put a secondary filter behind a paper filter or the OEM filter and look at the copious amount of dirt it collects. Dirt gets past any filter. If you don't believe me check out this link. http://www.bobistheoilguy.com/airfilter/airtest3.htm

Yes, K&N filters let in slightly more dirt than an OEM; I should say very, very slightly. It won't make any diference to the oil or the motor. Oil is designed to deal with a certain amount of dirt, and using a K&N filter is not going to bring the oil over the dirt-threshold point.

Just look at the secondary filter in the tests with a paper filter; it's filthy with dirt. Just think about all the dirt that is getting into your engine with your oem filter. Surely your engine can't survive with all that dirt grinding around in the engine can it? Tired of K&N bashing...

Bob's reasearch is very simplistic and does not measure the particle content passing the filter, it is as he basically says just an eyeball check. It's like looking at two dirty oil filters and and saying one is dirtier then the other, thus one filter is better then other filter. That is rather laughable to say the least, and I'm glad the mfg's of our cars don't design our cars that way.

Forgot to add that the ISO testing of any OEM filter will almost 100% of the time be better then aftermarket products. The Mfg standards are higher in almost 100% of cases then the aftermarket products because aftermarket mfg's do not want to spend the extra $'s to have equal or more efficient filter made when all they have to do is say they are better knowing there is no law against their statements as has been proven in various cout cases. One case was Mobil suing Castroil for advertizing their oil to be synthetic, because in fact it is not. Mobil lost the case as the judge ruled that word synthetic was just a advertizing type of trademark and not a discription of an oil. In other words the judge did not believe there is such a thing as synthetic oil. Go figure.

[dannym]

Originally Posted by wols0003

I'm going to defend K&N a little bit here from the typical bashing they often recieve on forums. Why don't you put a secondary filter behind a paper filter or the OEM filter and look at the copious amount of dirt it collects. Dirt gets past any filter. If you don't believe me check out this link. http://www.bobistheoilguy.com/airfilter/airtest3.htm

Yes, K&N filters let in slightly more dirt than an OEM; I should say very, very slightly. It won't make any diference to the oil or the motor. Oil is designed to deal with a certain amount of dirt, and using a K&N filter is not going to bring the oil over the dirt-threshold point.

Just look at the secondary filter in the tests with a paper filter; it's filthy with dirt. Just think about all the dirt that is getting into your engine with your oem filter. Surely your engine can't survive with all that dirt grinding around in the engine can it? Tired of K&N bashing...

Most medium efficiency commercial filters are 20/20 meaning they will catch 20% of particles over 20 microns.
I think the best you can get without going way overboard with cost is 30/30.
Nobody in their right mind would use a high efficiency filter like a hospital grade filter.

Danny

[engatwork]

Heck - they don't even run one on their own car.

[bodyart27]

i run a cold air intake on my nissan se-r w/ a k&n. it's pretty much a full time track car so i'm always going for top performance. there is no staock airbox anymore so it runs a k&n all the time

I dyno'd my '01 clk55 with and without k&ns (it takes two) and i netted a 14 lb ft increase in torque at the wheels! That translate to about 400 lb ft at the crank when the base rating is 376 lb ft.... so there is real power to gain

I only put in the k&ns in the clk55 when i go to the drag strip (which i've only done once and for the dyno run) - i have oems in the car now

somewhere on mbworld.org i have the dyno charts posted

[Hit Man X]

Mean Green filters trap better than K&N... not to mention are built better. Too bad they're not made for us in direct replacement versions, only universal and select vehicles.

[MTUpower]

Originally Posted by dunl

They're bad for any engine....they let it too much dirt.

If you use one, put a paper filter behind it and se how much dirt it catches that the K&N didn't.

How about marine engines? 98% of medium sided (800-2400 hp) marine diesels have a oiled gauze filter. Not much dust on the ocean....
So they do have a place that is within standard long term use applications- but it is not on a everyday driver if you want what is best for the engine and you plan on keeping the car according to nearly all well informed individuals.