Anyone just pick up a k/n drop in filter? Any problems, good, bad? Obviously it won't give the gains of an intake upgrade, but as a filter replacment that's reusable... good, bad?

 

anything is better than the piece of crap factory filter thats nothin but a 1" sheet of paper

 

I figured as much. It's about time to replace it, and I know for sure, one of those isn't going back in. Just a matter of wether it's worth spending 65 bucks on a k/n filter, or 270 for an entire intake upgrade.

Not sure if the mpg gain, if any is worth it.

 

Well, I'm going to weigh in on this.

K&N is a racing application and not something that a turbo powered diesel should use if not properly maintained. Understand that all oiled filters come with a certain amount of risk when it comes to over oil or dirt or whatever. They flow more air, no question but they also invite other issues.

I used a K&N on my 2002 for almost 3 years with no issues but I was almost religious about dealing with it.

Should you use the drop in heed this warning:
1. The filter must be oiled as per the requirements
2. The gasket that is used to seat the filter in the OEM box must be used
3. The edges of the drop in must be sealed to the rim of the OEM box with surgical or first aid type white sticky tape. Using this withstands heat and wet and is not an option to ignore.
4. Inspect the seating of the filter and ensure that it is correct.

The reason for the tape is that the suction force from the turbo can and does draw the filter away from the seat and can pull it into the draw tube making all sorts of mess and having the potential of running a truck without a full filter. I witnessed that on my drop in and I have witnessed similar with a plastic bag being drawn onto a BHAF.

If you follow the above you won't have any problems.

 

I have running a K&N alternated with an aFe drop in for about 40,000 kms. Both are oiled filters. I also run a gutted stock intake tube and have a 4" hole cut in the bottom of the stock air box. These filters get dirty very fast. If I travel on dirt or gravel roads they must be cleaned every 10,000 kms. This is probably due to the hole in the bottom of the box sucking air from the area in front of the wheel. I am investigating building a connection to the air box from an SRT 10 hood to cure this.
The K&N runs with less turbo whistle than the aFe flat drop in. The aFe is fun to listen to around town but not so fun to listen to when hauling the travel trailer and running at a constant 10 lbs. boost. So I run the aFe for the most part in the winter. With that said, I just purchased the new version of the drop in afe which is a cone shape similar to the K&N. It is close to the K&N for sound. I think that the aFe is capable of trapping more dirt than the K&N but as I said, in dusty conditions I watch them both closely. Most guys around here who are running a great deal of kms on country roads, are sticking to the factory filter.
By the way the gutted tube, 4" hole and K&N are good for 1.5 mpg when pulling the trailer.

 

If your asking for opinions - K&N are junk and dont belong anywhere near a Cummins. These engines require a LOT of air and this product doesnt filter it well enough, IMO.

 

I had problems with the kn.

 

only reason i ran k&n was cause it was a freebie for my 5.9...my 6.7 has never had anything since stock except the new Banks Ram Air

 

better than stock

 

Sounds like the drop in filters are not the best way to go then, if I'm reading all this right.