Thought I had a bad servo to the door that mixes temp. Turns out the servo is good. The shaft that the servo rotates is broken off! Looks like it has been "repaired" in the past as there is glue residue on the broken remnants and there are pieces of the shaft missing. Dealer estimate to repair is $900 but would likely be a couple hundred more as "They wouldn't look forward to performing this repair". Any thoughts or experience with this issue? The purchase of this Cobalt has been a mistake from day one.