Hi,

I am new to the forum. I have a Chevy 350 engine with turbo 400. I am getting a knocking sound in what seems to be the passenger rear of engine between about 700 to 1200 rpm (no tach so guessing), then it goes away.

I put the stethoscope on it but could not really determine it's location. However, if I was to do my best guess it seems upper rear passenger.

I adjusted the rockers running to 3/4 turn.

The rockers are adjusting fine and do not seem to clack when adjusted. By theory, if a lifter is bad, wouldn't the rocker not adjust or keep clacking if it is bad enough to cause a knock sound?

Also pulled the trans bell pan to see if the torque converter nuts were rubbing or if there was any wear on the flexplate but did not see anything.

Running 5-30w oil. Already put in Lucus wear protector honey and marvel mystery oil. Just ran it mostly for hours no change.

In conclusion, the engine runs awesome past the 700-1200 rpm no knock sound. Lower the idle down and it goes away too.

Your help is appreciated.
Charles