130k, seems to be coming from the rear bank. lessens or goes away with a few rpm. Its there cold or hot. Sounds like a diesel pickup when at idle. Any know/comman problems with the valve train? Just wanted some suggestions before I tear into it. Alot less noise with the serpintine belt off but its still there. G.

 

Sounds like it could be a push rod knocking due to a collapsed lifter.