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The Truth About K&N Intakes

5869 Views 32 Replies 18 Participants Last post by  [email protected] Automotive
So Ive heard the good and bad about K&N products and thought that I would see for myself. So, I decided to buy the K&N intake and see what happens... How bad could it be? K&N is a trusted brand right? Im not going to bash them, but here is my personal experience: 5k miles ago, I spent all of my part time paycheck and bought one of these intake systems, spent a good 45 minutes installing it and was quite impressed when I was finished. Noticed better throttle response and a great open element turbo sound.

5k miles later now after checking/rechecking the intake every few hundred miles to make sure nothing had come loose/shifted and everything was solid, I decided to take a look at the turbo to get an idea of just how much dust and dirt this thing was letting in. I opened it up and was immediately shocked to see that the inner walls of the intake were caked with dirt!

This truck is my weekend driver/hauler and sees a slowly-driven dirt road once every other week (by itself and NOT driving behind somebody else who has kicked up a dirt-road-cloud). I had purchased a 6637 at the same time for fear that this might happen and have installed it immediately (still using the K&N intake pipe).

So for any other folks looking to upgrade their intake, I say forget the fancy intakes that go for several hundreds of dollars and look for the NAPA 6637... Cant be any worse than my K&N at only around $40.

Will upload photos when I can get to a computer.
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looking forward to seeing the pics.
I bought my truck used and it had the k&n intake on it. I run a dryflow filter tho. So the 6637 filter fits on there?
I bought my truck used and it had the k&n intake on it. I run a dryflow filter tho. So the 6637 filter fits on there?
Sure does. Fits right in and clamps down like it was made for it...so I guess the K&N wasn't a total loss :thumb:
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Here are a couple of the photos taken yesterday. You can see the thick layer of dirty sludge built up around the inside of the intake.

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Here are a couple of the photos taken yesterday. You can see the thick layer of dirty sludge built up around the inside of the intake.
Thats oil residue from the CCV, perfectly normal.
A K&N ...guys don't even use them on quads and bikes anymore....pass to much dirt.
Thats oil residue from the CCV, perfectly normal.
I know the CCV is going to leave an oily residue on the inside of the intake but all of this dirt mixed with it is normal? :look:
i did seem to see dirt in the oil. appon removal of the factory system the oil seemed clean. HOWEVER i have drivin my K&N on dirty dusty nasty roads for about 30,000 miles and my tube and turbo show nothing near that bad or dirty. so perhaps you clamped the filter on and left a gap at the bottom or something.... i mean yes there was more dirt in the turbo than stock but not that bad overall.... although i do use a heavy coat of oil on my filter.
i did seem to see dirt in the oil. appon removal of the factory system the oil seemed clean. HOWEVER i have drivin my K&N on dirty dusty nasty roads for about 30,000 miles and my tube and turbo show nothing near that bad or dirty. so perhaps you clamped the filter on and left a gap at the bottom or something.... i mean yes there was more dirt in the turbo than stock but not that bad overall.... although i do use a heavy coat of oil on my filter.

I checked every few hundred miles to make sure there were no chances of having any gaps anywhere :dunno:

But I have moved on to the 6637, so I'll let yall know how this compares to the K&N (under the same conditions to minimize variables) in another 5k miles. We shall see which one is better (for me) :liar:
Thats oil residue from the CCV, perfectly normal.
Anybody else think this is normal??
wipe the tube out and get it all cleaned up or the dirt will eventually travel into the turbo. p.s you need to get a ccv mod because your tube seemed awful oily for only 5000 miles....
wipe the tube out and get it all cleaned up or the dirt will eventually travel into the turbo. p.s you need to get a ccv mod because your tube seemed awful oily for only 5000 miles....
Cleaned the heck out of the intake and got all of that grime out :thumb: Thought about CCV mod but am still on the fence about it... I like the idea of catching a little of the debris before it makes its way into the engine. Guess I'll just be cleaning it out more.
I know the CCV is going to leave an oily residue on the inside of the intake but all of this dirt mixed with it is normal? :look:
Oil yes dirt no, but from looking at the pics all I could see was oil residue.
That's not normal. Whens the last time you changed your oil? IMO the best setup is a K&N(or similar) pipe with the 6637 filter
That's not normal. Whens the last time you changed your oil? IMO the best setup is a K&N(or similar) pipe with the 6637 filter


Last oil change was about 3500 miles ago. Thats what Im rockin as of yesterday (K&N pipe with 6637).
Ya that doesn't just look like old oil. About when I get to the end of my oil lifetime(5K) I notice a bit more oil in my intake, I guess maybe it vents a bit more out when it sheers down.
Oil residue is normal, dirt is not. Just about every direct injection diesel I have seen has a CCV routed to the air intake. Honestly its a lot cleaner oil residue wise than most I have come across.
Oil in the tube yes after its entry point from the ccv..good, well as far as emissions yes its better to burn the vapors but it does coat the IC's which will change the efficiency a little.

Cleanable filters...never good thats why I will NOT sell them.
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The PO of my truck had a K&N and it was bad. Not as bad as yours but it was only on the truck for 5k. i switched to a section of 4" tube and the 6673 filter 9000 miles and two oil changes ago and this is what it looks like. It's better than the factory airbox and the K&N by a long shot.


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