Where is the thermostat on a 2.4 liter D21 4 cylinder Nissan pickup?

In a 2.4-liter D21 4-cylinder Nissan pickup, the thermostat is located in the engine's cooling system, typically at the end of the upper radiator hose, where it connects to the engine block. To access it, you usually need to remove the upper radiator hose and the thermostat housing. Make sure to drain some coolant before removing the housing to avoid spills.