Thanks swoop. I will be sure to inspect the t-stat and the sensor for any signs of deposits and gunk/goo as well as trying for a sighting of the exposed radiator cross tube when I dump the coolant for the repairs.
I have to wonder about how specific OEMs request ECU parameters be set up for their application when the choose an engine for their build.
I know from experience that the Dash 14 Komatsus with K-21 will shut down to idle only when step 2 overheat is still present (though events over heat step 1 and step 2 will be recorded in ECU memory).
I'm getting a visual (in my imagination) of this mechanic fumbling around on the overheated engine idling in safe mode trying to figure out why it won't throttle up.............while the radiator overflow hose is venting into the hood insulation. Well, you get my drift I'm sure.