My trusty, well maintained, 850 GLT has just experienced pcv system problems that I'm hoping to share with others as well as get some advice from others who've experienced the same.

My car has 120k mi. and the pcv system was last inspected at 110,000 The flame trap has always been clear on inspection and there has never been oil in the throttle body (air intake). Now there is oil in the throttle body, an oil soaked but not clogged flame trap and to my horror a completely clogged vacuum tube? (the small tube running from the flame trap housing to a manifold with several small tubes stemming from it). Latest inspection was prompted by oil leaking from apparently rear main seal/oil pan gasket onto garage floor. Also an oil ooze from the oil cap.

Now, all the while the car has run just fine. There has been no change in performance, no check engine light, and there are no codes showing up in the diagnostic system.

I've replaced the clogged lines and there still seems to be too much pressure in the crank case (which the pcv system is supposed to regulate). My chiltons manual leaves me in the dark on how the pcv system works on my car (what is the small tube leading from the flame trap to the manifold exactly and what is the manifold with all the small tubes comming out of it - there is an idle air motor that feeds from/into this manifold). I would like to clean/replace any clogged or failing parts that would lead to the crankcase pressure. I've heard mention that there is a breather filter in the air filter box but I don't see one. I have the 5254S engine and Jetronic Injection system.

AND, is my rear main seal toast as a result of all of this??

Any help from experienced volvoers greatly appreciated on this one!

Mark Sloo
Minneapolis, MN
'65 122s, '93 850 GLT