Oil in Intake Pipe is Common?

[Chad989of2000]

Haven't messed around with the car for some time as it has sat for nearly a year in my garage with random start ups. Took it for a drive yesterday and when I got home I took off the intake as I'm planning on installing an ETS fmic and I just want to check things over. I noticed a bit of oil pooled up just in front of the turbo at the intake pipe's end. I remember some oil being okay but this was a good little pool...no white smoke or anything. Other info...rebuilt 4G63 w/ 3000 miles and an Evo III 16g with similar mileage. Just checking to make sure this is common...gonna do a leakdown test this evening just to make sure.

 

[Barnes]

Do you still have the valve cover breather port connected to your intake pipe?

 

[Chad989of2000]

Valve cover breather port as in the passenger side one? Passenger side one is going into an oil catch can while the one to the rear of the valve cover is going through a pcv valve into the intake manifold.

 

[belize1334]

Does the catch can just terminate or does it run a second line back the intake pipe? How long have you had the catch can and have you removed the intake pipe since it was installed?

 

[Barnes]

Yeah, that's the one. Hmm, so no ports going back into your intake. How old is the turbo?

 

[Chad989of2000]

Quoting belize1334:
Does the catch can just terminate or does it run a second line back the intake pipe? How long have you had the catch can and have you removed the intake pipe since it was installed?



-Catch can terminates, I empty it every once in a while. I have removed the intake since having the catch can and have noticed a slight film of oil but not quite this much.

-Turbo has about 3000 miles on it...built by RRE and ported, it was new when I got it and put it on my car. No white smoke throughout the rpm range.

 

[belize1334]

Hm...

The thing to do is consider all possible ways that oil can get into the intake. Basically, there are three...

1) With the breather connected you can get oil vapor being pulled out of the valve-cover into the intake. If you have a catch that is recirculated to the intake then this effect is minimized. If you have a catch can that is terminated then this path is completely eliminated...

2) If you BOV is recirculated then you can get oil blowing out of the turbo into the intake route and then back into the intake pipe with the BOV vents. If you BOV is not recirculated then this too is eliminated.

3) It's possible for the turbo to be so leaky that you get oil leaking backward out of the compressor housing into the intake path.

Beyond that I see no way for oil to get to the intake pipe so it's gonna have to be a process-of-elimination game to figure out where it's coming from...

 

^^^I agree with all of this....and if it were #3 then you'd definitely have some oil throughout the other parts of the IC piping. what does the inside of you current intercooler look like??

 

[Chad989of2000]

And the answer is yes, it is common and acceptable. Leak down went fine...engine is still strong, did a compression test also...all is strong and uniform across the board. Thanks for all the input fellas, looking to dyno the car when I finish up with everything.