Ok, so it has been a long week. But should the wrist pin and rod assembly be able to move back and forth (left to right) inside the piston? (2200) 99' Cavalier.


I have a new replacement piston assembly that appears to be 1997 and earlier and there is almost no play allowed.


0.094" btw.


I tore it down because of chattering coming from cylinder one. Besides the rod bearings looking like they got hot and some play I am not sure what was causing all the racket up top.

Perhaps the extra play at the rod bearings was causing the designed amount of wrist pin play to sound like slap? Or slap was occurring because of bad rod bearings? It was mostly on decel but started showing up at idle and otherwise.

"A damaged or worn connecting rod bearing will produce knock under all speeds. During the early stages of wear, connecting rod noise may be confused with piston slap or loose wrist pins. Connecting rod knock noise increases in volume with engine speed and is at its loudest on deceleration." [Justautorepair.com]

Sounds like my problem. There is some scorching on the rod bearings.