RE: '06 Impala LT rapid tapping noise?
 

Yeah, it was nice she got the new engine. However, a factory rebuilt would have been okay as well. Factory rebuilt engines are good quality. Either a new or factory rebuilt was fine. Just didn't want Bubba from the shop rebuilding it.

Definitely was not piston slap(PS). The infamous GM PS issue happens when the vehicle is cold started and after it warms up the noise vanishes. This noise started out as intermittent and then became constant. Now, possible it was a bad piston pin. Slap though would be no.

I still think it was a bad rod bearing or rod itself. I don't think the tech doing it had a clue what to look for.