The system functions as follows. Cold coolant from the bottom of the radiator enters through a hose to the water pump and is pumped through the main channels of the engine block, as well as through the oil cooler (where available). After cooling the engine cylinders, combustion chamber and valve seats, the coolant is supplied to the thermostat, which is closed during the initial period of time. The coolant also passes through the heater and returns through the cylinder block to the water pump.
On a cold engine, coolant circulates only through the cylinder block, cylinder head and heater. When the coolant reaches a certain temperature, the thermostat begins to open and the coolant flows through the upper hose to the radiator. Since the coolant begins to circulate, it is cooled by the air flow when the vehicle is moving. If necessary, the air flow is increased by the operation of the electric fan (ov). After reaching the base of the radiator, the coolant has cooled and the cycle will repeat.
When the engine warms up to normal operating temperature, the coolant expands and is forced into the expansion tank. When the engine cools down, the cooling system is fed from the expansion tank.
On automatic transmission vehicles, some of the coolant flows from the base of the radiator through a cooler mounted on the transmission. On vehicles with an oil cooler, coolant also flows through it.
The electric radiator fan is controlled by a temperature sensor, which turns on the fan when a certain coolant temperature is exceeded.
Attention! When opening the cap of the expansion tank on a hot engine, care must be taken, because. Escaping hot vapors and coolant can cause severe burns. Do not allow coolant to come into contact with clothing or body paintwork. Otherwise, rinse the surface with plenty of water.
If the cooling system leaks when the engine is hot, place a cloth over the filler cap on the expansion tank, slowly unscrew the cap to relieve pressure. When all pressure in the cooling system is relieved, remove the filler cap.