Too much Crankcase pressure?

[FWBennett]

Ok I just got through installing my rebuilt 700r4 tranny and everything under there is spotless! Fired up the beast and noticed smoke (blow by) comming out of the dipstick hole - put the dipstick in - the smoke stopped but I've got oil comming out of the lower part of the dipstick hole (where it meets the pan and on the other side of the motor it looks like maybe the oil pan is leaking where the pan meets the block the wire loom is right there and it's hard to determine. I knew I had some oil leaking but this is the clearest sign I've had of exactly where from and what's causing it. I recall reading a Forum topic where someone mentioned that a vale or something on the motor is supposed to create a slight vacuum - I'm thinking that part isn't working. Can someone refresh my memory and tell me what valve that is - what it looks like, where it's located and if it's serviceable or do I just replace it OR if I'm way off base here - set me on the right path!
- thanks!!!!!!

[britannic]

CDRV=Crankcase Depression Regulator Valve. It's the large shiny (when new; cadmium coated) canister on top of the valve covers (location varies according to engine type and year) which is connected to either the valve cover or oil filler and the intake manifold.

They can get gummed up and jammed; I cleaned mine out and it helped a lot, but it got even better with a new one, which was only $17.00+shipping from www.gmpartsdirect.com (http://www.gmpartsdirect.com) .

[catmandoo]

on an 84 it should be up front next to oil fill cap

[FWBennett]

OK I pulled the EDR Valve - there's plenty of air flow through it (as tested with compressed air) so I checked down stream and the path is clear into the Oil Filler tube, checked up stream all the way into the turbo's intake manifold. Sooo is there too much blow by??? There's no other signs that the motor isn't performing well (no over heating or loss of power etc.) Does the blow by deminish as the motor warms up?

[whatnot]

If you have a turbo, you do not want it going to the intake manifold. It need to have the hose go from the CDR valve to the intake hose or aircleaner box before the turbo.

[britannic]

Whatnot said:
If you have a turbo, you do not want it going to the intake manifold. It need to have the hose go from the CDR valve to the intake hose or aircleaner box before the turbo.

Otherwise the turbo boost is going to pressurize your crankcase. In order to replicate the CDR function in the N/A engine, the connection is made between the air cleaner to turbo air intake, to use the modest vacuum created by the filter's drag.

[FWBennett]

It's going to the turbo's intake (suction) side of the housing (no pressure from the turbo there) You mentioned the "drag from the air filter" - so I'll have to button it all up and see if that bit of drag makes the differance - I had the air cleaner housing off so that I could get to the shift cable of the tranny - that's when I noticed all the smoke comming from the dipstick tube.
So is that much blowby normal? I guess if you've got 20:1 or so compression it's gotta go someplace?
- thanks
-F

[britannic]

That amount of blowby you describe isn't normal, unless the CDR is so gummed up the crankcase cannot vent and so builds up too much pressure.