Thread: Engine spraying oil at high RPM

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I did perform a compression test. Cylinder 6 was low (135) and all others were around 160. I have not performed a leak down test.

I did contact the vendor (Mercury) about the cracked freeze plugs but they didnt even respond as this motor was sent to me free because I found out that the 1st motor I bought from them didn't have the forged pistons as advertised on the pamphlet i show in the original post. Im wondering if they didnt replace freeze plugs whats the chance they didnt do anything with the oil galley plugs as well?

The engine does not have any cooling issues and has always ran around 148-151 degrees. Its typical oil pressure is 45 psi at idle and at full throttle its pegged the gauge at 80 so I do not know how high it actually goes. My other 383 does this as well but has never had an oil spray issue.

when i got the oil pressure alarm it didnt show any oil pressure on the gauge.

The PCV valve did not come out of the valve cover and it does not have a hose going to the air cleaner.

for the life of me i cannot figure out where the oil is coming from when it blows everywhere. there is so much all over then engine bay but non on the engine itself.

Originally Posted by axm0z5h

The PCV valve did not come out of the valve cover and it does not have a hose going to the air cleaner.

You say that the PCV didn't blow out of the valve cover, but more important that it does NOT have a hose from the PCV to the air cleaner? What is hooked to the hose connector tube on the top of the PCV? The hose to the air cleaner, or to the base of the carb provides the vacuum pull to evacuate the crankcase, and without a hose that pressure will blow out through the PCV like a demon. That could be the source of your problem.