I will try to condense.
1.) Ignition Key stuck, broken key cylinder
2.) Rough Idle, compression 50LB off in #1 cylinder.
3.) Dealer #1 said bad exhaust Valve, unknown reason.
4.) Dealer # 1 would not replace head, sent off to "clean' and replace exhaust valve.
5.) Dealer # 1 said repaired after 2 weeks and test drove 30 miles.
6.) Dealer # 1 did not test drive and transmission solenoid 1 failed after I drove off of lot.
7.) Dealer # 1 replaced transmission solenoid after 5 more days.
8.) Still bad idle and now sounds like a diesel, took back to dealer #1 - 3 more times they said no problem don’t come back.
9.) Took to other Dealer # 2 said converter was bad due to rough idle and miss, they replace.
10.) Took to dealer # 2 three more time over 2 weeks, they said there is a problem and they don’t "reuse" heads they replace them, they think head was "cleaned" wrong so dealer # 1 fault. Engine may be damaged beyond repair because Dealer # 1 would not help after 1st repair.
11.) After 5 days at dealer # 2 GM refuse to let them take head off to find problem says diesel noise and rough idle normal.
12.) I asked GM to escalate case and that Dealer # 2 needs permission to find problem.
I hope I was clear...