General information about the cooling system (Renault Symbol 1)

The cooling system is of a closed type and consists of the following main elements: a radiator located in the front, an engine water jacket, a water pump driven by a timing belt, an electric fan, a thermostat and connecting hoses. A small additional radiator is installed on cars with an automatic transmission. A separate expansion tank is installed to compensate for thermal expansion and to top up the coolant.

The thermostat valve opening temperature is 89°C, the valve fully opens at 101°C. The thermostat valve stroke is 7.5 mm. The pressure in the cooling system is 1.2 bar. The cooling system uses one 3-pin sensor, two contacts of which are used to transmit information about the coolant temperature to the injection system ECU, and one for indication in the instrument cluster. Depending on the coolant temperature, the injection system ECU controls the operation of:

• injection systems;
• engine Cooling Fan Relay;
• coolant temperature warning light, which lights up when the temperature exceeds 118°C. The radiator electric fan is switched on at low speed by the fuel injection system ECU if the coolant temperature exceeds 99°C, and is switched off when it cools below 96°C. The high speed fan is switched on when the coolant temperature reaches 102°C, and the high speed is switched off when the temperature is below 98°C.

After the ignition is switched off, the injection system ECU enters the monitoring mode. If the coolant temperature exceeds 103°C for 5 minutes after the engine is stopped, the low-speed engine cooling fan relay is energized. If the coolant temperature drops below 100°C, the fan relay is switched off (the fan operating time cannot exceed 12 minutes).