Rebuilt Engine bearing wear
Years ago I had a noise problem pretty much like yours, I just could not find the issue. I have decided to tear it apart and triple check everything. It was pure luck while removing one of the pistons and dropping it on the bench and heard an every so slight click. I found one of the steel struts cast into the piston was loose and making the infamous clicking noise. It maybe something to look for if you decide to look deeper into your engine noise.
AUTOTHERMIK® / HYDROTHERMIK® pistons have cast steel strips and are slotted at the transition from the ring area to the skirt area. These pistons run very smoothly and are preferred for installation in car engines <<<<<< from Melling's Web Site
Years ago I had a noise problem pretty much like yours, I just could not find the issue. I have decided to tear it apart and triple check everything. It was pure luck while removing one of the pistons and dropping it on the bench and heard an every so slight click. I found one of the steel struts cast into the piston was loose and making the infamous clicking noise. It maybe something to look for if you decide to look deeper into your engine noise.
AUTOTHERMIK® / HYDROTHERMIK® pistons have cast steel strips and are slotted at the transition from the ring area to the skirt area. These pistons run very smoothly and are preferred for installation in car engines <<<<<< from Melling's Web Site