General information
The engine cooling system operates on the thermosiphon principle with a water pump and fan. The system is sealed and operates under excess pressure, which raises the boiling point of the coolant, thereby increasing the efficiency of cooling. The radiator cap is equipped with a control valve that does not allow excessive deviation of the internal pressure in the system from atmospheric (in both directions).
The coolant is forced out of the radiator through the valve into the expansion tank during thermal expansion and returns to the radiator when the engine cools down after it is stopped. The coolant temperature is controlled by a wax-filled thermostat. The thermostat is located in a casing attached to the engine block (on 3.0L models) or on the intake manifold (on 4.2L models). In order to prevent the development of corrosion, the cooling system must be filled with a mixture of water and antifreeze containing anti-corrosion additives.
The water pump is driven by a V-belt (common with the generator) from the crankshaft pulley.
The thermostatic fan clutch is filled with silicone fluid, the viscosity of which changes significantly with temperature, which allows automatic adjustment of the fan speed depending on engine speed and the intensity of air flow through the radiator. This reduces engine power loss and background noise intensity when driving at high speeds
A bimetallic spring at the front of the clutch controls a valve that controls the amount of fan slip.
On vehicles with automatic transmission, transmission oil cooling tanks are built into the radiator.
The text was borrowed from here (www.NISSANBOOK.ru)