Since the my 89 740 (with b230ft) was new it leaked oil out the oil filler on top of the valve cover. Is that normal? I want my valve cover to stay clean, but this has been a thing since the beginning.

 

You mean the oil cap? Make sure the gasket (seal) is tight. If this has been happening since new, may be the valve cover oil cap opening is not perfectly round, or may be the cap itself is deffective. It's one of those three things...

 

you can buy a new gasket at IPDUSA.com for about $0.80, or buy a new cap at the auto parts store. ALso check and clean the Flame trap, that is the most likely cause of blown oil.

 

Could be wrong but I don't think a turbo has a flame trap.

Replace the rubber oil seal under the oil filler cap.

 

+1 to the seal, i had the same problem.

Flame trap is the same as Crankcase vent?
then yes, they do. under the intake manifold. it is part of the long tube that wraps to the intake hose over the valve cover.

 

well, according to rock auto they do.

 

You know, I think teh Volvo filler cap and gasket are junk. I replaced two gaskets with OEM gaskets and they both split in short order and leaked when they weren't spilt. It's enough of a leak to make things look messy, not enough to spread oil around.
Anyway, I went old school and cut a gasket out of pigskin.
NO MORE LEAKS!!!!!

Regards, Andrew.

 

I'm sure RockAuto will sell you a flame trap for a turbo, as will a Volvo parts guy. However, there is no flame trap in a Volvo turbo.

There is an oil separator box and ventilation system, same as normally aspirated. There just isn't a flame trap insert. You could put one in I suppose.

 

Mine had a flame trap, until I threw it away about 3 years ago. I'm convinced it's just a government reg. So that's no prob. The oil separator is what I started with a few years ago. It seemed to have a flow of air, but when I put it back on it made no difference. So I don't think that's it. Plus when I did that my engine started to hunt at idle and I still haven't gotten rid of that problem yet. Maybe it's the cheap gasket I put on the manifold. **Back on topic** Since it's leaked from day one, I think it could be warped. I need to check valve lash so I might mill it when I get it off. I've tried different seals and caps (I got one old classic chrome cap and three newer ones plus the original from junkyards) and even cut a piece of gasket material to stack under the seal to make it tighter. I like that pigskin idea. I might give that a try.