View Full Version : Rear Main Seal Leak

10-08-2005, 09:56 AM
I have an 87 GN that I bought new. The day I brought the car home, the rear main seal was leaking. While it was under warranty the dealer replaced the seal 3 times and utlimately short blocked the engine. About two months after the short block was replaced, the leak returned and is still present to this very day. In the last ten years, I've had the rear seal replaced with an after market seal that is supposedly better than the old rope style. Still leaks. In fact, I just had it replaced last month and two weeks later, the leak is back.

I've finally concluded that the real problem is something rather than the seal. (Yeah, I'm a slow learner.) I have also replaced the PCV valve several times, but notice I still get oil blow out around it. Could it be that I have crankcase ventilation problem? What else can I do besides replacing the PCV valve? Or, has anyone out there had a similar problem and found some other cause for the leak at the rear main?

Any help is much approciated.

10-08-2005, 10:41 AM
Look very closely around the back of the valve cover on the passenger's side (It's a pain to see and you'll probably have to look from under the car).

Also look at the back of the intake manifold, especially where the heads, intake and block all meet ... very common for that seal to dry out and leak.