The first dealer I went to did not hear the growling that I heard constantly. They did not take it any farther.
My next scheduled oil change I went to the other dealer, I told them not to go down the same path as the other dealership.
They heard the noise and replaced the rear rotors, growling is now gone.
They now have a new customer.

 

I had my rotors turned a year ago and growl went..Now it's back and GM technical have told me it's 'normal'..
What kind of BS is that !
Glad yours is fixed though.

 

These guys seem to know their stuff, they also mentioned turning the rotors down and said that does not do the trick. Maybe the hubs are warped, but when they replaced the rotors the growl went away.
Hey, maybe in a year it will be back, I don't know.

 

I took mine in to have the height adjusted and get an alignment and while doing that the tech noticed the noise from the rear rotors. I hadn't really noticed it. They told me to just bring it in on the next service and they'll resurface them because they get glazed and that it was a known issue and covered under warranty. I'm about ready for an oil change so I'll do that then.

 

May be truth to the glazing as I feel better pedal now as opposed to before the rotor swap. I would not have thought warped rotors would effect the brake pedal.Smoother, quieter stops now.