Rear Main Oil Seal Leaking

[ddeluca]

Go for it man.. I love my new 09 247 LSV..

I seen some nice changes in quality and attention to detail.

You will see such a difference from an 07 or older...

Good things are happening at Malibu...

Let me know if you have any questions and don't hesitate to get the 8.1 450 hp motor on the 247.. It is a must have.

[BillFooter]

Repeated rear main seal leaks could be caused by blow-by. If the crankcase is pressurized it will push the oil out somewhere.

I guess my next question would be, whats causing the crankcase to pressurize ?

Cylinder compression that is leaking past the piston rings will cause the crankcase to pressurize. Sometimes that could be from the rings sticking or perhaps a broken ring. Excessive crankcase pressure can force oil out of the engine block through valve cover gaskets or crankshaft seals.

[medicdiver]

Could also be caused by excessive end play on the crankshaft. That is easy enough to measure while engine is out. That was common on the old ford 302/351 engine family in the trucks, and mustangs. I think they all came leaky from the factory. I havent heard too much about leaking seals on the GM motor though.

[BB LSV]

Repeated rear main seal leaks could be caused by blow-by. If the crankcase is pressurized it will push the oil out somewhere.

I guess my next question would be, whats causing the crankcase to pressurize ?

Cylinder compression that is leaking past the piston rings will cause the crankcase to pressurize. Sometimes that could be from the rings sticking or perhaps a broken ring. Excessive crankcase pressure can force oil out of the engine block through valve cover gaskets or crankshaft seals.

Well I got her back last night and was told that the valve cover was leaking, because it was loose...... They said the PCV valve was good. So I will let you know what happens from here. I am taking her out in today to check it out and make sure everything is ok.

Is there a way to check the crank case pressure? If you pull the oil fill cap, if there was too much pressure, could you tell from there?

thanks

[Pistol Pete]

There's really no way to test crankcase pressure. There is always some pressure in there due to a little blow-by and the windage that gets generated from the rotating masses around the crank. I wouldn't bother taking the oil cap off with the engine running, you might get oil coming out of there.

[BB LSV]

There's really no way to test crankcase pressure. There is always some pressure in there due to a little blow-by and the windage that gets generated from the rotating masses around the crank. I wouldn't bother taking the oil cap off with the engine running, you might get oil coming out of there.

My hands were to big to cover it anyways. it didnt seem to use any oil yesterday. I have a couple of white rags under it, and will see if it leaked any over night. Crossing fingers