K&N problem

[ken1mod]

Gentlemen,

 

About a year ago I had a clogged Cat converter in my motorhome. When they removed the device (in Canada) I had the opportunity to look at it. The front surface was covered in what looked like simple dirt. The passages in the cat were tiny, on the order of .020 inch by recollection. These tiny passages will trap anything. By the way, the MH was dead, had to be towed and would only idle. The dirt was loose and could be brushed off the surface. At the time, I thought that these things could be cleaned by blowing them out from the back.

 

Anyway, this MH had a K&N filter installed on it. A couple of weeks ago mdub posted results of a filter test on this site with K&N having poor filtering results, they seem to only stop the birds. But K&N did have the least initial restriction.

 

Anyway, I just removed the K&N from my truck and went back to paper. I think it is possible that these see-through cotton elements may be responsible for cat clogging and all the problems that causes. Clogged cats are a big price to pay for a microscopic power increase.

 

Any thoughts?

 

Ken

[Guest chevydeerhunter]

I bought a K&N for my truck and had it in there for about 6 months, after a really bad sand storm, I decided to wash it out and reoil it. As I was holding it up, I remember saying to myself, "man, there sure is a lot of light coming through this filter." That's when I decided that in the long term, the K&N is not for me. Racers swear by them, but remember that these engines are usually torn apart and gone through on a regular basis and aren't run as a daily driver. The K&N's serve their purpose, but not for me on my daily driver.

[ken1mod]

That is what I think too. Racers and daily drivers live in different worlds. Anyone want a used K&N element? Trash is picked up tomorrow.

 

Ken

[mcreyaufmiller]

I have had a K&N on my truck for over 100k miles, I just replaced my cat this past week.

[Bish]

I have had a K&N on my truck for over 100k miles, I just replaced my cat this past week.

 

<{POST_SNAPBACK}>

 

 

 

I've had a K&N FIPKII for 145K and still on original cats.

[phire]

K&N is utter junk. I used to be a die-hard K&N fan myself and wasted my money on every single car I bought buying those things. Not only do they not filter a d**n thing, they reach maximum capacity VERY QUICKLY! They need FREQUENT cleanings in order to stay breathable. I'm an AC Delco filter fan for life. Couple hours of googling and reading a few high calibur studies, real studies not some kid driving around for a year with each filter and giving us his "documented" results. Here, lemme link you to this ISO 5011 Air filter test using a REAL air filter test machine. you know, professional grade. Check this out... http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

 

Read everything carefully so you understand why certain filters rate poorly. I never could understand why the vets always bought AC Delco filters... I thought, man... what a buncha cheapass's, I want the BEST in my car! Anything stock usually sucks right? Well, since I do want the best in my vehicles... I will no longer be buying K&N. The ONLY application that K&N's shine through on is the race track where the car sees only an hour of run time tops and that's only to keep out large debris. They don't even flow all that much better, but they do by a slight amount so it's only practical that they're used on the most highest performing machines where every .09HP matters, otherwise you're just throwing money down the drain and mucking up your engine and eventually killing your gas mileage as they clog really fast. I assume they clog quickly due to the oil element. If it weren't for the oil, they wouldn't filter at all. lol

[Mr. Smith]

Alot of shrill bashing of the K&N... I have one on my T-Bird since new and it has over 120K on it with zero trouble. Sounds to me like possible maintenance problems to me. But hey I suppose for all the owners of K&N's that have no trouble there are 10 others who can't figure out how to open their own hood and yet try to clean and re-oil them and wonder why their vehicle runs like a$$

[rmreid]

I've run K&N filters on every vehicle without an issue, and for every negative article test you can find a positive one.

In fact I know of a GM dealership that sells and installs K&N filters and CAI's on vehicles and will do the wash/re-oil also

To me the benefit is that for $40.00, I have a filter for the life of my vehicle that I can wash and reinstall over and over as often as I want which for me is twice a year.

During the down time (for washing, drying and re-oiling of the K&N) I pop back in the factory air filter which also lasts me the life of the vehicle.

 

To each his own

[toneman]

Folks--the reason is simple as to why K&N (and similar) air filters are getting a bad rep, especially when used on late-model GM vehicles...improper cleaning and/or oiling of the air filter itself! It has been proven time and again that issues such as fouled MAFs were almost always due not because someone was running a K&N air filter, but because he overoiled it! I think that there is even a GM TSB about it too--it doesn't necessarily knock the use of such filters in general, just that problems may arise due to improper maintenance of such.

[AB Silverback]

I had a K&N filter in my '92 S10 Blazer for a while but took it out when the mechanic that I took my vehicles to said that there was a lot of dirt in the intake tube just past the filter. I was living in the Prairies at the time and there is a lot of fine dust always blowing around out there which seemed to make it through the filter. I washed and oiled the filter as per the instructions in the recharge kit so it is hard to say if I did something wrong or not. The mechanic told me that if I wanted to check if dirt was making it through the filter just put a smear of grease or vaseline on the inside of the filter housing past the filter, if any dirt makes it by the filter it will be caught in the grease and you will be able to see it.

[phire]

Most people will not notice an issue with a K&N filter directly, especially if they're cleaned and re-oiled.. Actually, one of the best things for a K&N in street applications is for it to become slightly clogged up, thus increasing its ability to filter, but of course, letting it go too far will do more damage, too. It's a high maintenence filter that doesn't filter well, it's common sense that in order to increase flow and decrease restriction which is the main selling point of a K&N, it's going to have to filter less. I used to use K&N religiously myself, cleaned them regularly, etc. The only car I use a K&N in now is my camaro which is rarely driven on the streets. You don't need great filtration on the track. ;) Another point of restricted air flow comes from the design of most stock airbox's, so putting in one that will flow better will give you the flow you want without sacrificing filtration.

 

Anyways, check out an ISO 5011 Certified test comparing K&N against the others. Yes, it flows much much better than the others, but its filtering is horrible and will reach maximum capacity much sooner than most others but that's not a problem for most people to clean and oil the filter often. But anyways, I don't base anything I currently believe from word-of-mouth or what's said on the back of boxes anymore. Everyone claims to be the best so that's no good.

 

Let me at least read you some numbers from an ISO 5011 Certified test in a controlled environment just so you don't think I'm basing anything from some backyard mechanic who tested a filter for a couple thousand miles and noted how he "felt" about each one. ISO 5011 Certified test numbers don't lie.

 

Filter efficiency is a measure of the filters overall ability to capture dirt.

 

AC DELCO - 99.93%

BALDWIN - 99.72%

AFE - 99.23%

WIX - 99.03%

PUROLATOR - 98.73%

AMSOIL - 98.63%

UNI - 97.93%

K&N - 96.8%

 

Not much to be said for K&N in efficiency there.

 

 

“Accumulative Capacity” is a measure of dirt holding/loading capacity before reaching the maximum restriction limit - Initial Restriction + 10 IN-H20.

 

AC DELCO - 573.9

WIX - 447.4

PUROLATOR - 388.7

BALDWIN - 388.2

UNI - 374.6

AFE - 232.5

K&N - 211.6

AMSOIL - 196.3

 

K&N ranked higher than Amsoil, I'm actually surprised, however Amsoil had a moderate rank when it came to filtration.

 

 

 

"Accumulative Gain" is the total amount of dirt that passed through the filter during the test.

 

AC DELCO - 0.4

BALDWIN - 1.1

AFE - 1.8

AMSOIL - 2.7

WIX - 4.4

PUROLATOR - 5.0

K&N - 7.0

UNI - 7.9

(Note: The Purolator was reported to have a seal malfunction during the test and passed more dirt than it would have with a good seal.)

 

 

 

 

Initial Restriction is the Filter under test’s resistance to flow at 350 CFM.

 

AC DELCO - 6.23

AMSOIL - 5.88

BALDWIN - 5.71

UNI - 5.4

WIX - 5.06

PUROLATOR - 5.05

AFE - 4.99

K&N - 4.54

(Here's where K&N really shines, it did the best on least initial restriction by 1.69 points. Is the slight amount worth it on your street car? Up to you.)

 

 

 

Dirt Passed Versus Total Test Time.

First number will be "Time to Restriction Limit, minimum" and the second will be the dirt passed in grams.

 

 

AC DELCO - 60, 0.40

BALDIN - 40, 1.10

AFE - 24, 1.80

AMSOIL - 20, 2.72

PUROLATOR - 40, 5.00

WIX - 48, 4.40

UNI - 44, 7.90

K&N - 24, 7.00

 

The AC Delco filter test ran for 60 minutes before exceeding the restriction limit while the AMSOIL and K&N tests each ran for 20 and 24 minutes respectively before reaching max restriction. In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms. Compared to the AC, the K&N “plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons.

[Rookie]

5/3 of all people know you can use numbers to prove anything.

[ken1mod]

Gentlemen:

 

I love the knowledge on this site. this is the kind of good, non-emotional, data we need to enjoy our trucks more.

 

Back to the original post, since the k&n passes roughly 20 times (not 20% more dirt, 2000% more dirt) more dirt than delco, where does this dirt go? It appears to me and anyone who has examined a modern cat that much of it stops in the cat converter. It did on my motor home. The passages in the cat are tiny and long. partially clogged cats reduce engine power and efficiency way more than slightly more restriction on the intake side. I have never seen an engine stopped by the dirtiest air filter. a clogged cat will put you on the tow truck.

 

I really enjoy my truck and would do anything for more power (who wouldn't?) but the polyrazmatazz claims of these manufacturers of filters, etc are appealing more to our emotions than genuine long-term fact. Besides that, the k&n guy looks sleazy to me.

 

Now, fender flares, that's my performance option!

 

Ken