2003 cts rumbling/grinding sound when accelerating
 

I've got a problem and I can't seem to pinpoint where exactly the noise is coming from. It's a 03 cts 3.2 automatic . When I'm driving and accelerating from a stop I hear a sort of rumbling sound. I first thought it was my waterpump (which was going out) but after I changed it . I still hear that rumbling noise. Then I found out one of my mounts was messed up pretty bad. I got it replaced today. And now I hear it even more. Has anyone dealt with anything like this? It only does it when accelerating

Grinding sound from rear of 03 CTS
 

I had this noise from the rear end like the tire is uneven.:mad:
I have changed tires and put new tires.:confused:
I changed the rear shocks.:confused:
I then changed the Deferential oil. Royal Purple:confused:
Then I changed the tires again to Michelin.:confused:
No luck:mad:
Then I put in two new hubs.:rolleyes:
All noise is gone car sails like on air. :)

I've got the same problem exactly after I bought my 05 CTS, I usually hear the rumbling noise and ticking sound after I start the engine every morning. Then after the car temperature has reached the middle the noise goes away. Can anyone help me find an answer to get rid of this noise. :-(