hi all,

I have a 89 740 gl in the shop. the compressions are all really good but there's some blow by coming out of the oil dipstick and the valve cover leaks pretty bad (the oil filler cap too). there's pvc valve on this thing is there anything else I can do or check to find out whats wrong?

thanks
mike

 

Volvo have a system called a flame trap instead of a pcv system.In between cylinder 3 and 4 look between cylinder 3 and 4 where the intake meets the engine.There is a big hose that goes to a plastic peice also there is a small hose that goes to it to.Replace the plastic screen inside the plastic peice.Also follow the small vaccum line to the intake and clean out the nipple on the intake.The nipple clogges up.You can use a small drill bit to clean out the nipple.If you still have the same problem after doing that the vent box is clogged and you will have to replace that to.