When the coolant reaches 89°C, a valve opens in the thermostat and the liquid enters the radiator, installed under the flow of incoming air in front of the car. The cooled liquid repeats the above cycle. If necessary (in hot weather, when driving at low speed) an electric fan is additionally switched on, which intensively cools the liquid.
The cooling system uses ethylene glycol based fluid - it is most suitable for systems with multi-metal components. Fluid should always be changed at the prescribed mileage interval. This is necessary not only to maintain its non-freezing properties, but also because over time, anti-corrosion additives lose their properties and metal oxidation products are formed in the cooling system, polluting it and worsening engine cooling.
Pic. 3.79. Scheme of the engine cooling system: 1 - engine; 2 - radiator; 3 - expansion tank; 4 - heater radiator; 5 - thermostat housing; 6 - fitting for air removal; 7 - oil-water cooler (for vehicles with automatic transmission); 8 - thermostat; 9 - water pump
The scheme of the engine cooling system is shown in fig. 3.79.