6.2max

A lot of these engines will have lifter tick, piston slap and even some rod knock. GM advises their dealers that this is the way engines normally sound. Apart from some lifter tick when the lifters bleed down and need to pressure up on restart I suspect there are some sloppy clearances causing the problem. I've been told by GM that up to 5 minutes of piston slap is fine and the rod knock was all in my head. Complete nonsense.