What are the signs?

[Low-Low-SIERRA]

When your pistons go bad. Does the truck make a clack noise when you turn it on and give it a little gas.

Thanks

[Plumpton]

I think it is a piston slap problem and from what I understand it isn't a mojor problem. GM knows about it. My truck does the same thing on cold mornings and then after a few minutes the noise goes away. Apparently it's due to the excess room where the connecting rod connects to the pistion pin. You can search for it on google and you can find a few good websites with some information.

Hope this helps.

[horse482]

When does it happen, when did it start, how loud is the noise? Need more info, y/m/m.