mjr46

^^^^^^could be main bearing rattle or crank walk due to a worn thrust bearing

kaggriff

mains dont fade from my experience. never thought about a thurst bearing.. Guess that is why i am going in to explore. ;-) really strange as it sounds like a rod fixing to turn lose when it is cold. when it gets to operating temps the noise goes completly away. got me a little stumped. So i am going to check it out just to be sure.

kaggriff

Also have had a manual oil pressure gauge on it. never wavers in oil pressure. would think if it was a main it would so signs there also.... but you know these motors better than i do. this is the first 347 for me. someone also mentioned that if it had cast pistons it could be a wristpin or piston noise. and that would explain it going away when warm.... I will get rid of the noise one way or the other. I cant help but to think it is not good on it. Thanks for any input MJR.