the engine runs hot and the coolant runs out some times
where is the thermostat located on 1992 Cadillac Seville
Yep! Right on top of the engine in the middle of the V between the two cylinder heads.
If you follow the upper radiator hose where it goes to the engine, it is connected to the thermostat housing. Whatever you do, make sure you do not open the cooling system when the engine is hot! Let is sit for at least 1-2 hours after driving before working on the cooling system.