I would like to know your thoughts about the following issue i am having with my CTS. After driving the car for about 10 mins, I hear a humming sound coming from the back when I press the accelerator slightly!! My brother and i were thinking it is either the back axle differential(?) or the exhaust system? By the way, the humming sound goes away if i move my foot off the acceleration padle.
At another forum (yahoo groups) a guy said that he also noticed the same issue, however it disappeared after replacing his exhaust with a modded dual exhaust system.
What is your input on this issue? please let me hear it.
Thanks a lot.