Update to this oddity.
Spent some time doing the tear down. Word to the wise: Some youtube videos that claim to be for ‘your’ car or truck? Double check. I’ll have to reseal the lower coolant hose intake to the block. (Thermostat is on the top on a 3.5, and not the bottom as some state)
Okay, enough whining. Replaced the thermostat. Removed the parts on the ‘front’ of the engine and after several hours (and even more cuss words due to rust) Had the water pump in my hands. The pump is fine. Impeller is attached to the shaft just fine and intact.
Now I’m glad to have pulled that apart- The timing belt is about 10k overdue for replacement and the belt was the factory and had a few fine cracks starting to form. The water pump I think was replaced (no branding) and does have some minor lateral play with the bearings in the pump. So yeah, those parts are due to be replaced.
Currently it’s sitting in pieces until next week when I get a couple of days off. Found the K-Frame is badly rusted out. From a safety standpoint it’s not ‘at risk’ at this time. But there is now a 2″ round rust hole dead center. I’m looking into replacement IF we can get the cooling issues worked out.
We took the thermostat back home and I dropped it into a pan with water at a rolling boil. The thermostat did open, but only about a millimeter. Being in a pot of boiling water that sucker should have gone full open. Just a crack of about 1/8″? Naaa, glad I replaced it.
So, the plan is to reseal the lower radiator hose intake. Dodge used an O-ring. Of course, it’s not available to purchase separately. Going to give the mounting surface a light coating of black RTV and snug the bolts down. (OF course, the bolts are pointed right into the A/C compressor)
Once the timing belt and water pump are installed, I’ll use the shop vac trick to purge out the engine block and cores. Maybe the cracked “Y” for the heater core caused the overheat and that took out the thermostat. I really do not know. But it’s going to be reassembled and I’ll see how it goes. If it’s back to normal and not overheating- I’ll look into the K-Frame as it’s due for inspection this month.
S-