Have a 2003 Rendezvous, with a 3.4 eng. Automatic.
Car started overheating and we stopped several times to cool down and add water.
On the 3rd overheat, the red dash light came on then we lost power and motor shut down.
I never saw water leaking from the engine and no water in the oil.
Would a bad thermostat chut down the motor and not allow starting?
If it gets to hot it will shut down as a safety precaution. If it overheats quickly it cold be a bad tstat, if it takes a while it oould be several things. When hot check rad for cold spots by putting hand on fins, make sure fans are inoperative. Then have it pressure checked, you may have a head/intake gasket problem.