Excessive Crankcase Pressure

[beckjm72]

Ok, I need some ideas.
I have an 89 TTA (#970) and evething has been restored. Motor has less than 1000 miles since a very good rebuild and had excessive crankcase pressure since day 1 (spits out oil through added breather on the valve cover and pushed the oil dipstick up and spins oil everywhere). I added a second breather on the other valve cover and it seemed to get a little better. The other day, I pulled out after driving it around a while (its a weekend driver) and barely got on it. Smoke (oil burning) started to come from hood and inside car and it started running rough (like only on 5 cylinders). Oil was all over the place (mostly crom dipstick pushing up), so excessive crankcase issue is still here. So here we go, what woudl cause this? new forged pistons and gile to fit rings by professional engine builder who specializes in turbo buicks. All I can figure is head gaskets or broken ring. Anything else I should check? There is no oil in water or vice versa. Cam has replaced with billet roller along with matching valve springs but for street use, not racing.
This thing is driving me crazy!

 

[robert lee]

What is the vac at idle ?

 

[TT/Ameasap]

Sounds exactly like a blown head gasket on the intake side. Do a compression test on all cylinders. Typically its #3 or #6

 

[TTA1163]

I've got the exact same issue going on with my car. Did a compression test a couple months ago and found one of the cylinders on the driver side was approx 20 psi lower than the rest. Bo is right, more than likely the head gasket is a goner which I intend on replacing. Will probably just pull the motor and give it a good once over and clean up the engine bay which is long overdue. Rob

 

[TTA984]

Been there and done this! It sound like a head gasket as noted above. Boost and knock don't mix, there are ways to suppress all the detonation and keeping them running good.