Thermostat — Checking and Replacing (Mitsubishi Colt 2)

Caution: Do not remove the radiator cap, drain the coolant, or replace the thermostat while the engine is hot.

Examination

1. Check the coolant level, tension belts and operation of the coolant temperature sensor.

2. If the engine takes too long to warm up, the thermostat is probably not closing completely. In this case, it needs to be replaced.

3. If the engine is overheating, check the temperature of the upper radiator hose. If it is cold, the thermostat is not opening and needs to be replaced.

Warning! Do not drive the car without a thermostat. The computer system will be open, which will lead to an increase in fuel consumption.

4. If the upper radiator hose is hot, coolant is flowing and the thermostat is open.

Replacement

5. Disconnect the negative battery cable.

6. Drain the coolant.

7. Disconnect the upper radiator hose from the thermostat housing.

8. Locate the thermostat housing located between the upper radiator hose and the engine.

9. If the fitting connected to the hose appears to be very worn, it may be further damaged when the hose is removed. If this happens, the thermostat cover should be replaced.





10. Unscrew the bolts and remove the thermostat cover (3.10).

11. Remove the thermostat from the casing and note how it was installed.

12. Remove any traces of old gasket and sealant from the surface of the thermostat housing and cover.



13. Install the new thermostat into the housing. Check that it is installed correctly (3.13).

14. Apply a thin bead of sealant to both sides of the new gasket and secure it into the housing.

15. Install the thermostat cover and tighten the mounting bolts to the specified torque.

16. Connect the hose and tighten the clamp securely.

17. Fill the cooling system with coolant.

18. Start the engine, wait until it warms up, check the operation of the thermostat and the presence of leaks.