Where is the thermostat in a 1994 Infiniti Q45?

Nissan does not install a gasket between the tstat housing and the tstat cover for this application. Use the appropriate liquid gasket sealant instead. The thermostat is located at the front of the engine, behind the water inlet from the lower radiator hose. It should not be confused with the water control valve in the water outlet housing that is located at the rear of engine..