You really know your field, and I respect this and hope that others appreciate your knowledge as well.
Thank you very much for all of this detailed information. (And everyone above!)
I understand the compression aspect at this point a lot better. This explains Cylinder 2-4.
I’m still a bit lost on what happened to #1 to cause the bent rod, but I’m getting closer to the full picture.
Given your explanations I am exploring the idea the piston rings on my car were failing and that both service places failed to recognize this fact by not having performed a dry and wet compression test. (Although I have more faith that the dealership might have.) I will ask about each shops methods of testing compression and Kia’s view of the quality of the rings when they took everything apart, especially for #1.
After gathering the information from the shops, I’ll call Wynn’s again and I will ask if a damaged piston ring would present a problem during their service procedures that would result in a hyrdolocked piston and thus a bent connecting rod. If that’s possible, I’ll suggest they update their manuls to have all technicians do a dry and wet compression test before performing these servics.
The explanation from KIA was that if the piston did lock, the service technician would have heard it and had to re-start the engine. In my book, if that happened - it’s still a major customer service “No-No”.
I’m only half trying to blame somebody - the other half of me is trying to understand how and why this happened so that it doesn’t happen to somebody else. (And I will tell anyone that asks never to have this service done, after reading all the other posts about fuel system cleaning.)
If my car’s hidden problems were the cause of the fuel cleaning service creating damage I will have to admit I was wrong, apologize, and pay for this mess. I readily admit I’m wrong, and most of the time assume I am wrong – it’s just that this time I have taken care of the car and there were no signs of problems before this mess started.