Posted by encinoman on September 09, 2003 at 13:13:34:
In Reply to: Loud knocking posted by Mike on 08/14/03 at 4:13 PM:
I had a similar noise and it was the main bearing. In that case the engine seemed to run OK, but ultimately needed an overhaul. The noise started after a hard run.
Years later it happened a second time, I had less warning. The engine started making the loud knocking noise during a 10 hour run. It started OK. It got worse over the next hour until it became unbearable. Finally it also ran rough enough that I didn't want to run it. Turned out the crankshaft was split in half, but the two haves were contained in a journal, so it would still start. Amazing that it turned over at all.