Might be the tensioner recall. They did it on mine thinking maybe that's what it could be but not in my case. Main reason I traded it in. However on mine it sounded like a cracked header or gasket leak.
I have 2 Shelby Razors (20x9) that I no longer need. These have curb rash and will need to be repaired. These are no longer made and are the GT500 offset. So these can be used with Brembos. Asking $100 each plus shipping.