I have just replaced the head gaskets in my D2. The truck has 198K. I have also replaced all other gaskets, plugs, wires, thermostadt(180). It starts and runs fine, reaches operating temp but then quickly runs hot. I Have flushed coolantant in the process of the rebuild and am taking my radiator to be tested today. I have bled the system as per rave ect. Also replaced coolant temp sensor, water pump is healthy. Top radiator hose is hot but lower hose is cold. The reason foe the new gaskets was a visible coolant leak on drivers side cylinder head. The heads were decked and new valve seals were installed by a reputable machine shop. Any suggestions would be greatly appreciated!!!!


rick

 

Ususally it points towards a faulty thermostat.

 

Agreed. It's rare but not impossible for a thermostat to be bad out of the box. Seems like there was another example of that on the forum in the last month or so.