The owner of the dealership said they drove that truck for 500-800 miles before they listed it, I highly doubt they didn’t experience the chimney smoke show from the exhaust. Not to mention as I walked with the salesman to go look at the truck he told me to just wait and he would bring the truck over to me. I don’t think that was a coincidence.This^^^^ would be my assent of the truck. The ring was fine when you left the dealer.. I would almost bet money on that. It broke on the drive home. I have seen it before.... mostly in Boats engines.
The ring becomes stuck to the wall each time it passes the spot on the wall it receives a little more damage. next thing you know you are fogging for mosquitoes.