Table of contents: General information ↓ Precautionary measures ↓
General information
1. Cooling system - closed type, includes a belt-driven pump, an aluminum radiator with an electric fan (two fans), heater radiator, thermostat and various hoses and sensors. The system pump is driven either by an auxiliary belt or by the timing belt, depending on the model. All models are equipped with a fan driven by a viscous coupling, which in turn is driven by an auxiliary belt. The system operates as follows.
2. Cold coolant flows through the lower radiator hose to the water pump, which forces it through the cylinder block, passages in the cylinder head, and (if provided) oil cooler. After cooling the block channels, combustion chambers, and valve seats, the heated coolant passes through the heater radiator and returns to the block through the water pump. The thermostat on a cold engine is closed, preventing the passage of cold coolant into the engine.
3. Once the coolant reaches a certain temperature, the thermostat opens and the liquid circulates through the radiator of the cooling system, passing into the engine through the lower hose. The heated coolant enters the radiator through the upper hose. In the radiator, the liquid is cooled by the oncoming air flow as the car moves forward. If necessary, the air flow is additionally created by the fan (fans). After passing through the radiator, the coolant repeats the cycle.
4. The fan operation is controlled by a viscous coupling. The coupling is driven by an auxiliary belt and transmits rotation to the fan via a temperature-sensitive liquid clutch. At low temperatures, the impeller rotates freely on the coupling. At a certain temperature, the internal clutch valve opens, the clutch is engaged and the coupling transmits rotation to the fan. If the temperature drops, the valve closes and the impeller rotates freely again.
5. The electric fan is triggered by a command from the thermostatic sensor. When a certain temperature is reached, the sensor is triggered, power is supplied to the fan - the fan rotates. When the temperature drops sufficiently, the reverse process occurs.
6. On models with automatic transmission, a cooler for the transmission's hydraulic fluid is built into the radiator. The automatic transmission is connected to the radiator by two tubes, through which the fluid circulates through the cooler, remaining within the operating temperature range.
Precautionary measures
Do not attempt to open the expansion tank cap or touch the cooling system components when the engine is hot - there is a serious risk of scalding. If the cap must be removed, (although this is not recommended), first, you need to relieve the pressure in the system. Cover the lid with a thick cloth to avoid scalding and open it slowly. When the hissing stops, indicating that the pressure has been relieved, carefully open the lid. If the hissing starts again, wait until it stops. Stay away from the lid at all times.
Avoid contact with skin or painted surfaces of the vehicle. If contact occurs, rinse immediately with plenty of water.
If the engine is hot, the electric fan may run even if the engine is not running. Keep your hands, hair, and rags away from the fan while working under the hood.
When working on a vehicle equipped with air conditioning, read the warnings in the paragraph 10.