Ever since day one - I get a tap/pin/knock sound from my LS6 - on this Z06 - mostly around 2000 - 3000 RPM. It doesn't matter whether I warm the car or not .. or even after driving it in 70 degree weather, after 2 hours - and I am now at 1800 miles - IT STILL DOESN'T GO AWAY! What do I do? Dealer said it was normal .. I cannot stand it .... I am going insane now ... I will show everyone at BG when I get there! Help ! What should I do ?!