oil in intake

[catmandoo]

my 92 with a 6.5 n/a worked great used maybe a quart in 3000 miles has right at 110,000 on it and the intake was dry inside and i mean spotless.now after putting on my banks it has an oil film on it,wet like ya poared oil in it and drained it and i traced it back to the cdr pipe where it comes into the intake pipe,yes it has a new cdr valve. and i also put a little restriction in the cdr hose cutting it down to about half but still does it. any ideas on how to cure this or just live with it. i assume the turbo is creating more suction than the cdr can handle.i'm to the point of restricting it half again.

[ucdavis]

My understanding of the CDR is that it replaces blow-by much like PCV. So it is necessary to at least the extent req'd to equalize cranckcase pressure. Too much restriction is going to cause that pressure to accumulate & make itself noticed elsewhere.
I just looked into the intake of another 6.5 w/CDR & it to had a thin film of oil @ about 110,000, so your's sounds about par.

[pannhead]

dont restrict it or a little oil in your intake will be the least of your problems...if restricted you can start blowing seals etc

[britannic]

Expect more oil in the intake, since the turbo is going to cram a lot more air flow and thus make the CDR work harder.

If the engine starts surging/accelerating without throttle input (mechanical IP only), then do check the CDR, otherwise enjoy the performance.

My intake always has a film of engine oil since the Banks install; it'll help lubricate the intake valves as well.

[catmandoo]

ok sounds par for the coarse,one other problem that did bring up this question is on the old banks air filter box the intake hose comes out the bottom and makes a sharp 90 degree bend into the turbo,well i took it and put it on this 6.5 with my homemade aircleaner pipe and took it out and put about 50 miles on it and when i got back i could see oil seeping out from under the air chamber so wondered if it was the cdr pipe or the turbo so took the hose off and it had swelled to about 3 3/4 inch instead of 3 and i couldn't get it to hold on to the turbo without slipping off. so now i modified my intake pipe again and used the silicon hose, much better now instead of about 8 to 10 inchs of hose i only have 2 inchs. used 2 3 inch mandrel bent 90 bends cut all but about 1 inch off the straights welded them together and now my filter sets right under my hood intake duct for ram-air.next up is replace the cobbled up pipe i made from the turbo out ,got me a mandrel bent pipe today for that but i'm gonna have to cut the flange off and weld a 90 on top into the turbo.if anybody needs a mandrel bent headpipe for the 92-94 6.5s i found a place here in iowa that sells them for 65.00

[charliepeterson]

The CDR is supposed to shut off tight ounce you start moving. The suction from the turbo pulls the diaphram against the spring and closes off the oil spray. If the diaphram breaks down then it can't seal tight and will pull oil all the time. I wouldn't worry about a small film but if it's wet?

[catmandoo]

well wierd thing today thought as everyone else has oil in the intake with the turbo i pulled my little restriction which cut it down maybe a third of what it was, and tonite pulled the airfilter and intake pipe off and it was dry as a bone inside,the only thing i can think is on the new pipe i made i have the cdr pipe come up from the bottom whereas before it went in the side.

[britannic]

Originally posted by charliepeterson:
The CDR is supposed to shut off tight ounce you start moving. The suction from the turbo pulls the diaphram against the spring and closes off the oil spray. If the diaphram breaks down then it can't seal tight and will pull oil all the time. I wouldn't worry about a small film but if it's wet? Here's an excerpt from gmctd's post about CDR operation:

Oil at the compressor inlet is normal for a functional CDR.
Excessive oil consumption can be result of non-functional CDR.
Controlling excessive blow-by from worn piston rings is not a function of CDR.

Leak at front OR rear main seal is normal for functional CDR.
Why?
Leak at rear only, or front only, or even both, is normal for functional CDR, where crankshaft seal(s) have actually failed.

The CDR functions to limit crankcase vacuum to 4" to 6" on the water column.
27" of water = 1psi
2" mercury = 1psi

Early years CDR main failure was from rust, where the flow path was thru external breather cap. Result - no regulation.

Rube Goldberg arrangement of tubing and hoses was source of failure for the middle years engines.

The passenger-side valve cover mounting was the ultimate configuration, requiring only one external hose, proving most reliable.