It is the Jeep 4.0l and from what I understand, it is the last engine from the Rambler engine family. Sounds like there was enough water in the jackets that as the engine overheated after the pump locked up it was able to build up some steam the cyliders and protect them! Dad's begining to think that by the time she got to the house that the steam was starting to get out of the engine and cause the electronics to freak out and stall the engine. Looks like it didn't hurt the motor, but only time will tell. I did read something on another forum from somebody who has a friend who works at a Jeep dealer. They had an '87 or '88 4.0l Comanche come in with 77k on the clock and the engine locked up solid. Turns out the truck was still running on the factory fill of motor oil!