could it be? bottom end probs?

.....

Had the same problems but unfortuantly because of that problem I had to get a new motor

[jackal2000]

probably piston slap. 99-03 have this problem. there is a TSB out about the new coated pistons which comes assembled w/rods also.

[King Asoka]

^from what I hear thats a temp solution. the coating will wear with time and your right back to where you started.

and you can thank GM's exacting standards for this one.

.....

[jackal2000]

you should be able to get a rebuild for around $2k. just call around to different shops and what not, it took me a while to find a shop to do mine.