My 1993 volvo 850 glc is pushing alot of oil out of my fill cap and when aI remove the cap when the car is running there is alot of pressure behind it. I believe it's supossed to have some vaccum. Anyone know what this issue is the car seems to run fine. Thks

 

Well for starters, I'd replace the rubber gasket on the oil cap. Volvo recommends this every oil change, I believe. Also,. has the PCV system been done on your car? if not, that's probably part of your issue. There are plenty of writeups on doing that here. Keep us posted.

 

https://volvoforums.com/forum/volvo-850-16/pcv-breather-system-replacement-33970/

 

Hold off on replacing the oil cap seal. If you replace it before you take care of the PCV, it may build-up too much pressure and blow out your RMS.