2. The cooling system can operate in one of three modes. At the first stage, when the engine is started, until the temperature of the coolant has risen above a certain value, the coolant circulates in a small circle, from which the radiator is excluded. As the liquid warms up, the valve of the thermostat included in the system path opens and the radiator is included in the circulation circuit. The liquid passes through the radiator from top to bottom and is cooled as a result of blowing the radiator fins with outside air. With the constant movement of the car at medium and high speeds, as a rule, the flow of oncoming air is sufficient for normal cooling of the liquid. With a certain increase in engine speed, as well as when the temperature of the coolant reaches the next control value, the adjustable electric fan of the cooling system is activated, which pumps additional air flow, which significantly increases the efficiency of the radiator heat exchanger. The moment of turning on the fan and the number of its revolutions are determined by the engine control device (ECM) using data received from the coolant temperature sensor. The fan is switched on through one or more relays.
3. Depending on the type of engine and configuration, 1 or 2 fans can be installed on the car. On production models from September 2000 to August 2003 with gasoline engines and A / V system, in addition to the main one, an additional fan was installed, on models of a later release, one more powerful one was installed.
Note: The power of the main fan has been increased from 187W to 350W. On diesel models, a so-called cooling module is installed (see resist. illustration), which consists of a heatsink and two fans located in front and behind the heatsink. With the appropriate configuration, a capacitor of the A/C system can also be installed between the fans.
1.3. Cooling module: 1. Assembly of the front radiator (only diesel models with A/C); 2. Condenser K/V; 3. Radiator; 4. Assembling the rear radiator
4. The cooling system is hermetically sealed and tightly sealed with a expansion tank cap that can withstand a certain overpressure (1.2-1.5 bar), which provides an increase in the boiling point of the coolant and, accordingly, the efficiency of heat removal through the radiator. A decrease in the boiling point can lead to the formation of stagnation zones, which reduces the cooling efficiency of the engine. For this reason, the cooling system must be filled with a coolant of the appropriate composition all year round (see specs). If the internal pressure in the system exceeds a certain value, the excess coolant flows through the connecting hose into the expansion tank. As the system cools down, the fluid automatically returns from the reservoir to the radiator.
5. Adding coolant to the system is done through the neck of the expansion tank (see chapter 1).
6. In view of the above design features, such a cooling system was called closed, since it excludes any functional loss of the working fluid.
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