I know there's some sort of TSB or recall for brake lines rattling against the firewall or something, not sure about suction lines though.I just bought a used 2013 LTZ through a private sale. The seller told us the a/c needed to be recharged, as it was only blowing warm air. We still purchased it knowing it would likely need a compressor... which it did.
We replaced the compressor with an original GM part. Now, there is a horrendous vibrating sound heard only inside the car (or outside of you listen verrrrry carefully) when revving the car or when the a/c is on. We fiddled with a few things and found that the suction line (larger line entering fire wall) is what is vibrating against the wall and causing the sound. If it is manually pulled away, the sound is gone.
I have tried a couple different "padding" there today. It helps a little, but not much. Is there anything I can do to rid this sound?!