dipstick o-ring size?
 

so monday, I'm blasting up I80 in hot weather east of sacramento, and when I pull over somewhere past Auburn to get gas, my car is smoking .. damn, that grade is cursed (I've had several cars blow seals there). ahh, checking under hood, dipstick has pushed out a inch or so, and blurped oil over the intake side of things, dribbled down, 80+ MPH blew the dribbles back to the exhaust, made smoke. was only down about 1/4 quart from where it was when I'd left home.

A) I think I need to replace that o-ring on the dipstick, it looks flattened out.

B) this is a turbo so no flame trap and I'm pretty sure my oil separator box is in good shape, as is all hosing. why would I be getting so much crankcase pressure?

I really don't think your O ring on your dipstick is your problem!
Why don't you go back to the shop where you just spent all that money on the head job and see what they say? There's got to be some warranty after all, even though I am sure they will find something they "never touched" as the problem.

Pierce, I ran across this thread you posted back in July and I think I might have a similar problem and was wondering how you resolved it? My '93 Turbo runs great but once in a while my dipstick(which has a new o ring) pops up about 1/4 inch, usually after a high boost, highway run. It doesn't do it around town. Also, I traced an occasional leak at the bottom of my turbo oil return line where it plugs into the block. And I think they both happen at the same time which looks like classic, positive crankcase pressure. The first thing I did was check all the hoses and vacuum to the oil separator box and all is nice and clean. I know the turbos react differently than non-turbos at idle(no negative pressure) but what could be happening at boost? Any ideas?

UPDATE: Looks like my oil leak was not the turbo return line. It was the distributor seals. The old ones we're so hard and brittle I had to cut them off. It was leaking down onto the bell housing and dribbling down the right side, right over the return line. From there down to the engine/tranny bracket. Boy, you really have to be a Sherlock Holmes to find the source of oil leaks on these engines. But anyways, glad to have fixed it. So now I'll just watch the dipstick and see if it pops out.