Need help with with 02 Firebird

I have a 2002 Pontiac Firebird (V6) with 36,500 miles the engine makes this clicking noise when I start it up but stops when I start driving.

Problem #2 The sound from my speakers goes completly off when the heat is on for 15 mins or more or when the car gets hot.

I've took it to the 2 different Pontiac only dealers 4 diff times and they can not find the problem has this happen to anybody else can anybody give me any suggestions?