Inliners International Forums General Discussion Engines how do you know if you blew a main bearing...

my friend has a 1958 Chevy 235. There is a knocking sound, like something is hitting the inside of the oil pan. He dropped the pan after draining the oil. There wasn't anything in the bottom of the pan, but the oil pump screen is clogged up with old grease. Does a spun bearing make a knocking noise?

Dear M;

That era engine rarely (if ever) 'spins' a bearing.

How much oil pressure was there when it was running??

Loose main bearings will "rumble" when starting cold.

Move each rod from 'side to side' & see.

Good luck.