oil cap leak?

[trevor]

i have an 89' 760 turbo wagon. i am getting lots of oil leaking from what looks to be the valve cover gasket. i really think it is the oil cap. could the oil cap be defective causing oil to seep out?

[matthew1]

The gasket on 850 oil caps is known for this. I replaced mine because of this. Perhaps it is so on 760's

[760ti]

Make sure the flame trap isn't plugged, causing pressure in the crankcase to force oil out. That can cause all kinds of leaks. And the oil cap gaskets are prone to getting brittle and causing crappy seals, too. Check and see if the oil cap stays in place @ idle if you unscrew it. Normally, the vacuum of the engine will hold it in place. If the flame trap is plugged, the cap will dance around and fall off.

[elerner1]

I agree check flame trap. It is part of Positive Crankcase Ventilation (PVC) system and is located on intake side of motor. Its a cheap part to replace, but if it is blocked crankcase pressure will build and blow out oil seals. Refer to Hayes Manual Tune-up and routine maint.-Chapter 1, Section 36- PCV system.

[cwelk]

There is a gasket that is bad about drying out on the older 7 series. You can get it for a couple bucks at the dealer. I had the same problem on my 90 740.

[carol]

We also have an oil leak on our 89 740 GLE. We've tried the flame trap test (as mentioned above) and the vacuum was good, and have tried to rule out any other possibilities. It appears to be an oil leak from the head gasket, which would likely be labor intensive.

[Tore]

Hi Carol the oil leak may not necessarily be the head gasket. The most common is the valve cover gasket which is not expensive to replace.
Best regards

[carol]

Thanks for the tip... we'll check that possibility out. It's on the underside of the engine somewhere.