Hi Folks

My query relates to positive crankcase pressure on a ’92 940 2.3 non turbo 8 valve. I’ve read through the ‘700/900 Maintenance FAQ’ but would appreciate some specific advice on this problem if anybody can help.
It started around a month ago with oil leaking from the filler cap. I proceeded to check the PCV system over and found the hose to the manifold disconnected and blocked as well as the flame trap being only partially clear. Cleaning and reconnecting these items improved things noticeably but the leak persisted albeit at a reduced rate. I then replaced the ‘breather box’ and filler cap ‘O’ ring and the leak was reduced to a growing smear on the rocker cover around the filler cap.
For information, the engine has covered 160,000 miles still pulls like a train and does not use any water or oil to speak of. The leak is only noticeable when running at high load and RPM – the car is used on motorways regularly.
My query is, where do I go from here in terms of troubleshooting and rectification? Do I need to refer this to my Volvo specialist, or are there steps I can/ should take now? Moreover, do I need to worry about blowing main gaskets out?
Many Thanks in advance.

Thanks guys, I've cleaned it all up and will keep an eye on things over the next few days.

You may not have a problem. Even with the PCV system operating well, there will be oil splashed up into the oil filler cap. I've had this seep out even with a new gasket on the cap and the system working fine.

Your engine has the lightweight oil filler cap so the "jiggle test" doesn't work as well. That is the test where you turn the oil filler cap to the open position but leave it sitting in the opening. Then, if the running engine has positive pressure in the crankcase, the cap will jiggle around due to this pressure. If the crankcase pressure is negative, as it should be, the cap will be sucked down and remain steady. You can sort of do this on your engine by loosening the cap on a running engine and try to feel if the cap is being pushed out (bad) or sucked down (good). I've also done this with my hand over the open oil filler hole. Try these tests and see you can learn.

i think you will find that if you remove the seal fro mthe filler cap and use paper towels t o completely de-oil it, the filler neck and the cap each time you remove it the issue will go away - mine does...

I had the same experience after servicing my PCV components. A little wipe with a paper towel did the trick.

- Brian '93 945T

Did a 200 mile round trip yesterday, after the first 100 miles oil had leaked onto the roacker cover and was making its way towards the back of the engine.
Second hundred miles no problem at all. 10 miles to work this morning, leaking again. Makes little sense but will take some time this weekend to see if I can check the pressure at the filler cap.