Filter gets oily...

EmpirE231

Well-known member
Joined
Aug 12, 2021
Messages
507
Reaction score
411
On my twin turbo motor, the outerwears on the K&N filters get saturated in oil at the base of the filter.  I am not sure what is causing this, and thought I'd see what you guys think?  The filters are newer.... but have been cleaned and re-oiled about 4-5 times now.  I know they come heavily oiled from the factory.  when I re-oil them I let them sit for a day or so, and then blot it with clean paper towel to pick up an excess oil.  I am not noticing any extra oil on the inside of the filter.

My theory was somehow air / pressure being blown back out the turbos, causing some filter oil to blast onto the outerwears? is that even possible? It does have a BOV, and the turbos only have 1 season since being rebuilt. 

IMG_7288.jpgIMG_8115.jpg

 
Last edited by a moderator:
its probably from the rush of air going into the filter pressing the outwear against the oily filter and transferring oil to it when that happens.

 
I went to running the R2C dry filters. They actually filter better than the oil a gauze style and when they're dirty you just blow them out from the inside.

http://www.r2cperformance.com/
are they back in business? I remember not too long ago, they were going through some business issues.

also heard some mixed reviews on how well they filter 

 
R2C sponsored our two Class 1 cars for a couple seasons. Filters seemed good nd were easy to clean but then we started finding dust in the intake tubes. I ran R2C canister filter on my personal car and it kept breaking the internal mount and the filter would flop around letting a lot of sand into the intake. Fortunately my MAP was allowing oil into the intake and it caught the sand. We stopped running R2C and went back to Donaldson filters. 

 
are they back in business? I remember not too long ago, they were going through some business issues.

also heard some mixed reviews on how well they filter 
the one i had on my car (one for a dirt car 14" x 4' tall since i had a holley carb) worked great. never had any dust pass thru that i could see.

 
are they back in business? I remember not too long ago, they were going through some business issues.

also heard some mixed reviews on how well they filter 
I just bought a new one not to long ago.. Like 4 months or so. So far has been great. I am using an 18" long with 4" connection. No issues yet, no dirt in the intake. I have it completely supported at both ends so it can't flex and break or crack. Kartek still selling them.

 
Last edited:
I've been running the AEM dry filter for about 10 years. Never any dust in the intake.

 
S&B also make some very nice dry filters as well. They have awesome customer service also. They personally call you to make sure you're satisfied with their products even.

https://www.sbfilters.com/

 
So other than new filter recommendations.... nothing in my above post to worry about? is that pretty normal for anyone running K&N's on turbos?

 
So other than new filter recommendations.... nothing in my above post to worry about? is that pretty normal for anyone running K&N's on turbos?
I see it occasionally when prepping cars. Get a second set and swap them mid dune trip.

 
I see it occasionally when prepping cars. Get a second set and swap them mid dune trip.
Its' weird because the filters themselves aren't really that dirty after a 3-4 day trip... just the outerwears 

 
I had the same exact issue running K&N.

Only thing I could think of was that the outerwear was coming in contact with oil and "wicking" away from the filter. I can only imagine it would be much worse on a turbo car through smaller filters. Like the previous said its probably sucking outerwear to the filter and pulling the oil out.

That's good, they're doing their job.
Doing their job yes but I would think at some point becoming restrictive. The outerwear isn't really designed to be coated in oil and then covered in dust like a filter.

 
Last edited:
The filters are too small for the amount of air flow you are pulling  - there is now enough surface area - I have seen this fixed many times with larger filters - it also helps to keep the IATS down (more power when engine get hot after long runs)

 
Is it just me or does it look like those turbos got really hot?
not sure what type of paint the rebuilder used... but it was a nice grey when I got them back, and within 1-2 trips they faded to this pinkish color.

 
The filters are too small for the amount of air flow you are pulling  - there is now enough surface area - I have seen this fixed many times with larger filters - it also helps to keep the IATS down (more power when engine get hot after long runs)
IATS?

I've seen some cars with their filters all sucked in, which made me think the filters were definitely too small...  My filters still look look good.

 
Back
Top