Infiniti QX4 overheats and stalls

I am trying to help a coworker - the truck overheated once under highway conditions, they replaced the radiator and the thermostat around labor day, then just after halloween the same thing happens during city driving. now the nissian shop says it needs the whole engine… the engine cranks up, and idles by itself with no hesitation, and NO SMOKE! cranks on first try too!

I suggested the thermostat was not really changed, and the clutch type fan needs replacing, I have also considered the water control valve, but its unlikely

What Model Year Is This Truck, How Many Miles On It, And Does It Consume Any Coolant Between The Times That It Overheats?


the truck is 2001 infiniti QX4 - roughly 78,000 miles, I was not told that it takes any oil, coolant, or anything out of the ordinary. I thought about just driving the truck around until I could re-created the problem… I also considered the rad. cap…