I have a 89 pickup with a 22re 5speed. It has developed a knock in the mid range, only audible under no load. I can't hear it at idle or under load. I hear the knock primarily if I'm coasting and give it gas in a lower gear, before the gear catches up. I've had it on the timing light and notice the knock starts as soon as the timing advances out of the low RPM range. Timing chain appears to be under tension when I pulled the valve cover. Reset the TPS and cleaned the throttle body to no help. I'm not sure if this is a ping from improper timing advance. If it was a bearing I would expect to hear it across more of the RPM range and under load. Not really sure what to test from here. Any ideas?

 

Hi… my truck does the same thing… did you figure out the problem?

 

Yes, It was the #1 and #4 cylinder main rod bearings.