Squealing Noise When it Gets Warmed Up

[Rose88]

Well, knock yerself out. Sounds like fun rebuilding a new motor. Been there and done that a few times.

Rear main seal is also leaking that right there is enough to warranty the engine. They are sending us a new engine and picking this one up. They had me look under valve covers and nothing appears to be rubbing. Also noticed metal in oil sample. So I am thinking it could be a bearing? Once they get engine back and tear it down I will know for sure. Thanks for all the response and help as this engine is under a warranty and didn't want to void it in any way. Appreciate all your guys time and answers.

 

[tank1949]

Rear main seal is also leaking that right there is enough to warranty the engine. They are sending us a new engine and picking this one up. They had me look under valve covers and nothing appears to be rubbing. Also noticed metal in oil sample. So I am thinking it could be a bearing? Once they get engine back and tear it down I will know for sure. Thanks for all the response and help as this engine is under a warranty and didn't want to void it in any way. Appreciate all your guys time and answers.

I had local shop rebuild one of my 350s years ago. I supplied core. They didn't check crankshaft or used another crank and the rebuilt motor's harmonic balancer wobbled to hell. The crank had a bent snout. They fixed it after I pulled it and took it to them. Get ready to waste another weekend!

 

[Rose88]

Well the culprit of the squealing noise was a pvc valve ran to the wrong location. Another reason to never let customer help....lol, but I should have caught it. It was pulling oil down away from pistons and causing a squeal. Checked Compression and leak down and its good. Fingers crossed!!

 

[Boaterob]

I would like to thank Rose88 for posting about this squealing problem. A friend of mine came across this thread after chasing the exact noise, under the same conditions. He bought the boat, not knowing of the issue. Sounded like a bearing on a belt driven accessory at the front of the engine, We ran it till the squealing started and took off the belt. Still squealed. Then he found this post. PCV valve???? How could that cause such a loud expensive sounding squeal? Someone installed a PCV valve on the clean air side of the system causing the crankcase to be under high manifold vacuum at lower RPMs. We don’t know for sure what was rubbing inside the engine, but I suspect it was the plastic timing cover, which would soften up with heat, getting pulled into the cam gear. Because of the good people on this forum, this scary expensive sounding problem was resolve for $0.
PS This boat may have been sold because of this problem.