I have a 06 GXP NA with the 5.3L engine. I have had this small like metal on metal noise when i hit a small bump on the road. I decided to investigate it today and could not figure out what could be causing it. I did notice that on the break pads them selves they had super tiny pieces of gold like metal on them i dunno where it came from. And on everything behind the rotors was a grease like substance. It was grey and very smooth and was on pretty much everything. the car only has 43000 miles on it and I have no idea where to start trouble shooting.
