The coolant circuit is thermostatically controlled. While the engine is cold, the coolant circulates only in the cylinder head, as well as in the cylinder block and heat exchanger. As the engine warms up, the thermostat opens a large cooling circuit. The coolant begins to be supplied by a constantly running pump through the radiator of the cooling system. The coolant flows through the radiator from top to bottom and is cooled by the air passing between the radiator fins.
When the coolant temperature is between +92...+97°C, the thermal switch turns on the radiator electric fan. The electric fan is driven by an electric motor and operates until the temperature of the coolant drops below +84...+91°C.
Pic. 2.171. Cooling System Diagram
Pic. 2.172. Cooling system components
Attention! The radiator fan may also turn on when the ignition is off. Due to the heat in the engine compartment, this may happen several times.
Thanks to the non-constantly running fan, the useful power of the engine is increased and fuel consumption is reduced.
The frameless thermostat of the cooling system has a solid temperature-sensitive filler.
The radiator of the cooling system is tubular-lamellar, aluminum, with plastic tanks. The coolant is poured into the system through the filler neck of the expansion tank, the plug of which has inlet and outlet valves.
Checking the technical condition
Check the pipes and hoses of the cooling system for cracks, damage and reduced flow area.
Replace defective parts if necessary.
Assembly
Pic. 2.173. Scheme of installation of the supply pipeline
Insert the O-ring into the groove at the end of the supply pipe, moisten the O-ring with coolant and connect the supply pipe to the cylinder block (pic. 2.173).
Check for a yellow mark on the inlet hose and connect the yellow marked end of the hose to the yellow marked end of the inlet pipe.
Note. Do not apply oil or grease to the O-ring of the supply pipe.
Note. Insert the supply line into the socket in the cylinder block as far as it will go.
Note. Removed O-rings are not reused and must be replaced with new ones.