Engine/Transmission (1994 - 1998) K&N (or similar) oiled air filters on a Diesel

[PGaither]

I don't think it was on this site, but I heard somewhere on a diesel site that using a K&N (or K&N style) oiled air filter is not good for a diesel motor because traces of air filter oil can find their way to the diesel injectors and harm them/and the engine possibly? Can that be true? Or was someone just wrong about that? I know about the filters and know how to oil them (lightly, don't over oil them), and let them dry overnight. So I'm talking about a properly oiled & dried air filter.

 

[moparguy]

OH Boy. .



I bet I don't get the first reply in here.



Here's the deal. Some (many) have reported two issues with oiled filters. 1. Oil pulled out of the filter due to the nature of the negative pressures produced by the turbo. This oil can cause reduced efficiency by coating the tubes of the aftercooler (intercooler). 2. Dust getting past the filter and poor oil analysis.



It should be noted that many members are running oiled filters with no problems.



The issues above are what lead to the discovery of the BHAF paper element filter some now run.



Good luck, Ronnie

 

[Hammer]

Ronnie. .

Guess what you DID get the first reply .



Now to answer your questions,I hope,and before I do I am donning my flame retarded suit... ... . Ok I am ready... .



Phil... .

There has been alot of "heated" debates on the oiled air filters and how they harm vehicles. Seems to me like a product dislike more than anything else to me. Have there been problems with the K&N style filters,I'd be lying if I told you no. Two of the biggest gripes have been fit of the filter to the box and over oiling. There are some who complain that they do not filter properly and allow dirt and grime to pass the filter,most which can be attributed to poor fit and seal. DC & Cummings BOTH,have issued a TSB about the use of aftermarket high flowing filters and not to use them(kinda funny DC did that and you still can buy them thru Mopar Performance).



Now as we pass the crapola and my thoughts. . (flame suit zipped,helmet installed)... .

I myself have used K&N products in a wide variate of conditions and applications,2 of which were dirt late models and sprint cars I owned or sponsored,and have seen the benefits of them outweigh the rumors. Most all of the Central PA area tracks are dry slick and dusty and when you spin a sprinter 8800-9600 rpms in that crap anything can fail. One failure we never had was a dust related one,other crap yes ,dirt no. On weekly Tetons cylinder walls would be clean with only normal wear showing no score marks from dust or dirt passing the filters thru carb or injection. I will stand by their products and do still use them in some of our applications. There were many feature wins with K&N products sitting on top of those motors.



Over oiling is a big deal with guys here. I think it relates to being in a hurry as guys wash them,spray them and I'd bet reinstall them without letting them sit some. One question I raised with a few of them in those "debates" who criticized K&N's oiling problem was did they do it correctly. There were even some of those who had the "Air-Sep" in their profiles complaining,which baffled me,as that product recycles the crankcase breather(oil fumes and oil) thru the turbo system,DUH. If you use it correctly(since you have done it before) you will find the benefits of the filters.



Hope this helps and I KNOW others will drop in. Its your truck,you know how to use the filters(oil styled,K&N-AFE-etc)make your choice and stand by your decision. Any questions feel free to drop me a note... ..... Andy

 

[PGaither]

Thanks...

Thanks Ronnie & Andie (Ronnie you did the first reply in!), Your answers were very helpful, and interesting, and confirmed what I believed annyway, just wanted to make sure it wasen't a different sittuation with a diesel as this is first diel (and I love it!).



Phil

 

[illflem]

Sort of sounds like who ever said that filter oil harms injectors also thinks that both air and fuel flow though them.

Don't think I'd believe anything they say after that.

 

[y-knot]

I agree that the over oiling can and will cause problems, but that is a operators problem. Just need to learn how to apply the oil. I usually wash mine in warm, hot water, then lightly blow it out with air. After it has dried, usually a couple hours in the sun, I apply my oil. I use spray bottle, that way I can get a fine even coat, I spray both sides. Let it it for 5-10 minuits, then take a clean cloth and dab it off, removeing any excess oil. These is an important issue, but with the K & N filter, the big problem is with the seal around the outer edge of the filter. It will leak, it's not thick enough to get a good seal. I use to use K & N filter sealing grease around both sides of the filter, that worked but I wasn't confident in it. I then went to the AMSOIL FILTER, it is a very good filter. It's design (cotton gauze, pleated) is simular to the K&N, but it has a very good sealing edge, and is washable and good for about 25 cleanings. The best part, besides the right fit, is it is less then half what the K&N sells for.