Thread: Tapping noise at idle.

possibly it could be a lifter sticking, or a wrist pin giving a piston a little play, this is all common gm problems. there was once a TSB on the wrist pins and GM's solution was to replace 4 of 6 pistons ( cylinders 1-4) it was a joke. on the vortec engines that came in trucks and SUV's, GM's answer for wrist pin cold start ticking was to replace the engines but then they felt that wasnt cost effective so they started doing pistons too for those.

Yea after all my research i've decided its probably lifter tick. I just don't drive the car for a few minutes after I have started it until the tick goes away. For my car it seems to be worse when the weather is warmer. Who knows.