A stuck open thermostat won’t allow the coolant to heat up. But while you have the head off, replace the timing chain and water pump!

 

Agreed, the stuck open thermostat did not cause the overheating.

Maybe a bad fan, or loss of coolant because of a blown head gasket. So the question is did the overheating cause the head gasket to leak (warped or cracked head or block)? Or did the damaged head gasket (warped or cracked head or block) cause the coolant loss that led to the overheating?

 

It was removed stuck closed

 

A thermostat that doesn't open will cause an overheat.