Parts of the engine cooling system
1. Radiator; 2. Expansion tank; 3. Drain plug; 4. Thermostat housing; 5. Thermostat; 6. Thermostat gasket; 7. Water pump; 8. Water pump gasket; 9. Pulley; 10. Viscous fan clutch; 11. Fan; 12. Heater outlet pipe; 13. Coolant temperature sensor; 14. Radiator outlet hose
The car uses a closed-type liquid cooling system with forced circulation of liquid using a centrifugal pump (see fig. Parts of the engine cooling system). It includes a radiator, water pump, thermostat, atmospheric expansion tank and viscous fan. On 4D56T engines, an electric fan with a plastic impeller mounted on the motor shaft is used, which is turned on and off by the electric fan on sensor.
The tubular-finned radiator operates under high pressure.
Pressure of opening of valves of a stopper of a jellied mouth, kgf/sm2:
- exhaust valve: 0.75–1.05 (greater than or equal to 0.65) *;
- intake valve: less than or equal to 0.05.
Attention! Since May 1991, a one-piece fan guide has been installed, which has increased the cooling capacity of the radiator.
The thermostat housing is attached directly to the water pump housing.
Opening temperature of the main thermostat valve: 76.5°C.
Attention! On 4D56T engines, the main thermostat valve starts to open at 82°C and fully opens at 95°C.
The vane type centrifugal water pump is driven by a V-belt together with a generator. The fan is mounted on the axis of the water pump through a viscous coupling.
Attention! On 4D56 engines manufactured since May 1991, the water pump capacity has been increased due to a redesign of the pump on the suction side.
Mitsubishi brand water pump drive belt MD159551.
The normal deflection of the belt when pressed with a force of 10.0 kgf on the middle of the branch between the generator pulley and the water pump pulley should be within 10–13 mm.