5.17.7. Replacement of the thermostat

Need for removal of the thermostat and its replacement can arise at unstable temperature condition of the engine: overheat or insufficient warming up. In this case completely it is not required to merge cooling liquid.
For check of the thermostat on the car launch the engine and touch the lower hose of a radiator — it has to be cold. After temperature of cooling liquid reaches 85–92 °C, the hose has to begin to heat up. If it does not occur, remove the thermostat and check its working capacity.
It will be required to you: a key hexagon "on 5", the screw-driver with a crosswise edge.
1. Remove a stopper from a broad tank. Turn off a stopper of a drain opening in the bottom of the right tank of a radiator and merge from it liquid (see. "Replacement of cooling liquid"). Wrap a stopper of a drain opening.
2. Weaken an inhaling of two collars of fastening of hoses on thermostat cover branch pipes...
3.... also remove hoses from cover branch pipes.
4. Turn out three bolts of fastening of a cover...
5.... also remove it together with the thermostat.

Note
Pay attention to a condition of a sealing rubber ring in a thermostat cover groove. Replace the ring which is strongly deformed, torn or lost elasticity.

6. Overcoming effort of a spring, wring out the fixing thermostat plate down and, having turned it in any direction, bring out of gearing with grooves.
7. Take out the thermostat from a cover.
8. Before installation of the new thermostat check it, having lowered in the water which is warmed up to 78–80 °C. Heat water, constantly mixing, up to the temperature (85±2) °C.
9. At a temperature (85±2) °C the rod of the thermostat has to begin to move forward from a power element. If it does not occur, replace the thermostat.
10. Install the thermostat as it should be, the return to removal.

Good advice
Further to exclude a possibility of leak of cooling liquid, before connection of hoses to a cover of the thermostat grease cover branch pipes with a thin layer of sealant.

11. Fill the cooling system with liquid (see. "Replacement of cooling liquid"). Wrap a stopper of a broad tank, launch the engine, check lack of leak of cooling liquid through connections of hoses of the thermostat and warm up the engine idling up to the working temperature to remove air traffic jams from system.