Stock gtr thermostat opens at 76.5c Most engines thermostats open much later..
Elk: No, they SEIZE. (Well, I guess when they seize, they cease.)
LOL
Yeah ive seen plenty of them seize.
Id first be checking your overflow bottle level, if its low do a presure test on the system. If not run the engine and check that both lower and upper radiator hoses get hot meaning the thermostat has opened. leave the cap off during this period making sure there are no more air bubbles coming out before you put it back on..can take upto10 mins or more.. Give the engine a rev to help circulate the coolant and remove air pockets.. Once this is done then check to make sure your fan clutch is grabbing once hot enough. If he has overheated it bad enough there is a good chance you have screwed the head gasket too.. Possibly do a Co2 test to confirm.
Deren