Cleaning K&N air filters
02-23-2009, 11:52 PM
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E55 AMG
Cleaning K&N air filters
Any tips on cleaning the K&N air filters? I just pulled out my filters yesterday and they were pretty filled up with dirt. 30K miles on them.
02-24-2009, 12:26 AM
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2006 Mercedes-Benz C230
02-24-2009, 12:30 AM
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02-24-2009, 12:33 AM
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2006 Mercedes-Benz C230
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02-24-2009, 12:36 AM
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E55 AMG
02-24-2009, 09:02 AM
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02-24-2009, 10:07 AM
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Honestly, I would just treat the K&N's as disposable. If you don't re-oil them correctly you could run into problems with getting oil in your MAF which could screw things up a bit. I don't think it is worth the risk. The K&N's aren't that expensive to make it cost prohibitive. Just my $.02.
Tom
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02-24-2009, 10:23 AM
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2003 W211 E55, 2003 W220 S600
Honestly, I would just treat the K&N's as disposable. If you don't re-oil them correctly you could run into problems with getting oil in your MAF which could screw things up a bit. I don't think it is worth the risk. The K&N's aren't that expensive to make it cost prohibitive. Just my $.02.
Tom
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02-24-2009, 10:26 AM
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2003 W211 E55, 2003 W220 S600
To chance the filter on a e55 you don't need to disconnect the Y tube. All you have to do is remove the 6 torx screws and you will be able to remove the filter.
02-24-2009, 10:44 AM
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'06 E55, '05 SLK55, a few others
Whatever you do, don't use anything but their cleaner and oil, and don't even think of trying to speed up drying it with compressed air. Be extra gentle, let it air dry, and lightly oil it. Any type of rough handling/washing, or trying to use gas or something similar to clean it will destroy its filtering abilities. It's not that much work and the only reason to ever buy another set would be to have zero down time (swap and go).
05-05-2009, 03:12 PM
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2005 E55
I just popped in a pair of K&N 33-2181 for my 05 E55. When replacing the air box, I noticed the verticle fit was a bit tighter, making it harder to screw in than with the factory filters inside. I did manage to get the box to seal, but is this normal for all of you who use K&N?
05-05-2009, 04:04 PM
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E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
Throw them away, K&Ns don't filter well at all. The way they work is by being less restrictive that means larger passages in the filter media. Yes they flow better, yes I am 100% sure there are gains. But you are totally missing the point of the filter in the first place. Our super charger has internal tolerances between the rotors and housing that can be less than .003 and at 22,000 RPM the last thing you want is dirt passing through it. If you have ever had a SC or turbo apart that has had a K&N on it, you will know of what I speak, and the mess they bring. OEMs cheaper filter much much better and no oil mess in your induction system.
http://www.nicoclub.com/articles.php?id=180100
http://www.nicoclub.com/articles.php?id=180100
Last edited by Yacht Master; 05-06-2009 at 09:01 AM.
05-06-2009, 03:21 AM
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C218 CLS63TT PP Edition1, W213 E63S
Throw them away, K&Ns don't filter well at all. The way they work is by being less restrictive that means larger passages in the filter media. Yes they flow better, yes I am 100% sure there are gains. But you are totally missing the point of the filter in the first place. Our super charger has internal tolerances between the rotors and housing that can be less than .003 and at 22,000 RPM the last thing you want is dirt passing through it. If you have ever had a SC or turbo apart that has had a K&N on it, you will know of what I speak, and the mess they bring. OEMs cheaper filter much much better and no oil mess in your induction system.
and i was thinking to get me these filters ><
any other ones you recommend ???
05-06-2009, 08:02 AM
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Throw them away, K&Ns don't filter well at all. The way they work is by being less restrictive that means larger passages in the filter media. Yes they flow better, yes I am 100% sure there are gains. But you are totally missing the point of the filter in the first place. Our super charger has internal tolerances between the rotors and housing that can be less than .003 and at 22,000 RPM the last thing you want is dirt passing through it. If you have ever had a SC or turbo apart that has had a K&N on it, you will know of what I speak, and the mess they bring. OEMs cheaper filter much much better and no oil mess in your induction system.
As far as there filtering quality is concerned, I invite ANYONE to go to their website for some great tech articles.
Like this one:http://www.knfilters.com/filter_facts.htm#RESULTS
or try this for oiling:http://www.knfilters.com/MAF/massair.htm
I have used K/N's now for well over 20 years and have NEVER had a single issue with them. That includes numerous races engines spinning around at 8000 rpm. I even have them in the wifes SUV for a few cheap extra horsepwoer. This is the first MOD that I do with ALL my cars that I have ever owned. Including a few BMW M's which several own line forums say cause problems with BMW's electronics and I say
See yeah
PS: I do not work for, nor receive ANY gratuity from K/N, just one happy customer
Last edited by MRAMG1; 05-06-2009 at 08:50 AM.
05-06-2009, 09:34 AM
#20
The debate about K&N filters has been going on as long as K&N has been around, and it won't end anytime soon.
Some of you may have already seen this, but a very highly respected BMW tuner, Jim Conforti, had independent testing conducted on K&N filters. This was the write-up:
This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.
BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.
The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.
The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.
The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.
Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?
Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.
The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.
Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.
Of course, K&N refuted the results of this report, offers its million mile guaranty (who keeps their car that long?), continues with its successful marketing tactics, and sell lots of oily filters. But after reading the results of Conforti's test, it made me think stock paper air filters do a fine job of filtering the air for daily driving. As Conforti noted, it's probably no big deal if you drop K&Ns in for a few track passes if you really believe they do anything, but personally, I don't think it's a smart choice to run them full time. YMMV.
Some of you may have already seen this, but a very highly respected BMW tuner, Jim Conforti, had independent testing conducted on K&N filters. This was the write-up:
This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.
BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.
The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.
The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.
The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.
Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?
Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.
The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.
Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.
Of course, K&N refuted the results of this report, offers its million mile guaranty (who keeps their car that long?), continues with its successful marketing tactics, and sell lots of oily filters. But after reading the results of Conforti's test, it made me think stock paper air filters do a fine job of filtering the air for daily driving. As Conforti noted, it's probably no big deal if you drop K&Ns in for a few track passes if you really believe they do anything, but personally, I don't think it's a smart choice to run them full time. YMMV.
Last edited by komp55; 05-06-2009 at 09:38 AM.
05-06-2009, 10:01 AM
#21
MBWorld Fanatic!
The debate about K&N filters has been going on as long as K&N has been around, and it won't end anytime soon.
Some of you may have already seen this, but a very highly respected BMW tuner, Jim Conforti, had independent testing conducted on K&N filters. This was the write-up:
This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.
BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.
The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.
The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.
The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.
Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?
Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.
The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.
Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.
Of course, K&N refuted the results of this report, offers its million mile guaranty (who keeps their car that long?), continues with its successful marketing tactics, and sell lots of oily filters. But after reading the results of Conforti's test, it made me think stock paper air filters do a fine job of filtering the air for daily driving. As Conforti noted, it's probably no big deal if you drop K&Ns in for a few track passes if you really believe they do anything, but personally, I don't think it's a smart choice to run them full time. YMMV.
Some of you may have already seen this, but a very highly respected BMW tuner, Jim Conforti, had independent testing conducted on K&N filters. This was the write-up:
This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.
BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.
The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.
The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.
The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.
Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?
Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.
The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.
Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.
Of course, K&N refuted the results of this report, offers its million mile guaranty (who keeps their car that long?), continues with its successful marketing tactics, and sell lots of oily filters. But after reading the results of Conforti's test, it made me think stock paper air filters do a fine job of filtering the air for daily driving. As Conforti noted, it's probably no big deal if you drop K&Ns in for a few track passes if you really believe they do anything, but personally, I don't think it's a smart choice to run them full time. YMMV.
K/N's response
K&N Response:
It is incorrect. The difference between 99.2% and 98.1% (his results) is 1.1% not 224% as he states!!! (bmwE34.net: who didn't go to school, Jim was measuring the amount of dust that goes inside the engine). Furthermore, does he realize that 96% meets OEM standards? K&N has been around for over 30 years and we sell over 2,000,000 units a year. If there were any sort of problem, one would think we would know by now and so would everyone else. One Internet "expert's" opinion is not reason for concern and should be taken loosely at best.
That information is 100% untrue. Don't believe all you read on the Net. Most is opinions not based on any sort of factual evidence. Our filters are tested by an outside, independent laboratory. They have been proven to stop at least 99% of particles on a SAE dust test. This test uses particles as low as the 0 - 5 micron range and goes up to 20 microns.
For comparison, a paper filter also stops 99% on the same test and the OEM minimum standard is 96%. Foam is generally the worst media with a typical efficiency rating of 75 - 85%. To get higher ratings, the foam must be more dense and therefore way more restrictive. The "tack" characteristic of a K&N allows for increase filtration without loss of flow as well. The testing procedure used is SAE J-726 using ISO Test Dust.
This test is the standard of the air filter industry. The test procedure consists of flowing air through the filter at a constant rate (airflow rate is determined by the application) while feeding test dust into the air stream at a rate of 1 gram per cubic meter of air.
As the filter loads with dust the pressure drop across the
filter is increased to maintain the prescribed airflow rate. The test is continued until the pressure drop increases 10" H2O above the initial restriction of the clean element (in this case .78" to 10.78" H2O). At this point the test is terminated. The dirty filter element is then weighed. This weight is compared to the clean element weight to determine the total Dust
Capacity. The amount of dust retained by the filter is divided by the total amount of dust fed during the test to determine the Cumulative Efficiency.
The K&N filter achieved the following results:
- Dust Capacity: 305grams
- K&N Cumulative Efficiency: 99.05 %
Holding the filter to the light is useless, pin holes are normal.
That is what makes a K&N filter. There are actually hundreds of microscopic fibers that cross these holes and when treated with oil, capture and hold the very fine particles. On the same hand, they allow the filter to flow more air than paper or foam. The filter is 4 ply cotton gauze unlike some competitors synthetic material filters. The synthetics do not
have the very small fibers that natural cotton does. Also, the oil can be pulled off of a foam filter contaminating electronic sensors. It will absorb into cotton and stay in the media. In fact, Honda and Toyota only recommend K&N filters when using aftermarket high flow filters as K&N is the only brand of filter the oil does NOT come off of. They will not cover a failed sensor if foam filters were used.
We got started over 30 years ago making filters for motorcycles and off road racers. The filters did so well that these guys wanted them for their cars and trucks. We started making filters for these applications and here we are today. If they did not work, we would not still be here and growing every year.
We now make filters for Chrysler/Mopar, Ford Motorsports, Edelbrock, Rotax Engines, and Harley Davidson. We come as original equipment on the 2000 Ford Mustang Cobra-R. We even made filters for the Apache helicopters used in Desert Storm because of maintenance problems with the original paper design. If they work in these conditions they will work for you.
Rick from knfilters.com
And yes I agree, this argument will go on forever.
Enjoy, I'm out of here
See yeah
05-06-2009, 10:18 AM
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2004 E55 AMG
Regardless of the test results, I too have never once had an issue with a K&N filter. Even if they truly do allow twice as much dirt in, I have never seen a case where that extra dirt actually made a difference in longevity. I would imagine that a piece of carbon breaking loose from the combustion chamber or piston dome(a normal thing) would have much greater potential to cause harm than some super-fine dust a filter let in. As long as the filter can keep bugs and sand out, I think the engine will live just fine. I doubt a piece of 2 micron dust is somehow going to scratch a cast-iron cylinder sleeve or gouge the rotor in a blower.
05-06-2009, 10:22 AM
#23
Didn't leave it out; I said K&N refuted the findings. You merely posted their lame refutation. We choose to differ, and I am of the more dirt = bad school of thought when it comes to engine air intake.
Last edited by komp55; 05-06-2009 at 10:30 AM.
05-06-2009, 10:28 AM
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Have fun
05-06-2009, 02:03 PM
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2005 E55
Sorry to be in the way of the quality discussion, but if I may intrude with the original subject just for a moment.....so with the 33-2181 k&n replacement, is it supposed to be a little bit harder to close the air box completely?
