crankcase pressure too high.
hi. you are on the right track, but its not actually oil pressure, so much as crankcase pressure. as pcv is an acronym for positive crankcase ventilation, as you can imagine, when the pcv becomes blocked or restricted, the crankcase pressure rises, and the end result is oil blowing out past seals, from around the oil cap, anywhere it can escape. eventually, you could have seals popping out, this happens if it becomes completely blocked, and driven without getting it fixed. you dont want to blow a seal.
to repair this, on a 940 turbo, is pretty simple. on the intake manifold, between #3 and 4 cylinder runners, is a little white sort of tee shaped connection pipe. this is partly where the problem lies. there is a hose coming over from the turbo area going to the top of it, and a short hose on the bottom, going down to the oil trap box. there is a small vaccum hose coming from the vaccum port, going to a brass nipple on the intake manifold. replace the white plastic pipe, (or clean it completely out, most especially the vaccum port...this is critical) replace the length of small vaccum hose, and again..extremely critical: remove and clean out the brass vaccum nipple from the intake manifold! if there is no vaccum to the pcv fitting, the whole effort is wasted.
its not too hard to do all this, and it will cure your excessive crankcase pressure situation. also a good idea to go ahead and replace the oil filler cap seal while you're in there. good luck with it, post back if you have any trouble.
