Hey plumber007,
I am sorry to hear that you are having concerns with your Cadillac STS. For clarification, did you recently purchase this vehicle, or did you have it serviced? Also, have you considered visiting your local dealership to get a diagnosis on this? If so, could you please send me a private message with your contact information, VIN, and preferred dealership so we can help you further with these concerns.
Best,
Alex H.
Cadillac Customer Care