Attention! If the engine overheats at low mileage, then the cause of this may be lime deposits that have clogged the radiator, or a break in the water pump drive V-belt.
Removing
1. Disconnect the wire terminal «masses» (-) from the battery.
Attention! This deletes data from the memory devices, for example, the security code of the radio. Before disconnecting the battery, please read the chapter «Battery - removal and installation».
2. Drain the coolant into a suitable container.
3. Remove cover 1 of the thermostat housing by unscrewing the mounting bolts (see illustrations 6.3 and 6.3a).
6.3 Remove cover 1 of the thermostat housing by unscrewing the fastening bolts. The illustration shows a 1.4-/1.6-liter petrol engine (K7J/K7M)
6.3a Remove cover 2 of the thermostat housing by unscrewing the fastening bolts. 2.0 liter petrol and 1.9 liter diesel
4. Write down the mounting position of the thermostat 11 in the coolant pipe and remove it (see illustration).
6.4 Record the installation position of thermostat 11 in the coolant pipe and remove it. The illustration shows a diesel engine
Examination
5. Measure the height of the thermostat and write it down as the value a (see illustration).
6.5 Measure the height of the thermostat and record it as the value a
6. Heat the thermostat in a container of water. In this case, the thermostat should not touch the walls of the container and should be completely immersed in water. Check the water temperature with a suitable thermometer (see illustration).
6.6 Heat the thermostat in a container of water
As soon as the water temperature reaches approximately +89°C, the thermostat valve will start to open.
The maximum travel of the thermostat valve occurs at a temperature of approximately +101°C. At this water temperature, the valve should open fully. This means that its stroke must be at least 7.5 mm. To determine the thermostat valve stroke, it is necessary to subtract the value a from the value b (see illustration 6.5).
Attention! Due to the fact that the full opening of the thermostat occurs at a water temperature exceeding its boiling point, the given data should be considered as indicative.
7. Make sure the thermostat valve closes when it cools down. Otherwise the thermostat replace.
Installation
8. Install the thermostat in the outlet pipe.
9. Vehicles with a 1.4-/1.6-liter petrol engine (K7J/K7M). Clean the sealing surfaces on the cylinder head and thermostat housing. Apply sealant to these surfaces «LOCTITE 518». The layer of sealant H should be between 0.6 and 1.0 mm and should be applied as shown in the illustration.
6.9 Apply sealant to these surfaces «LOCTITE 518». The sealant layer H must be between 0.6 and 1.0 mm 5
10. Cars with 2.0 liter petrol engine and 1.9 liter diesel engine. Secure the thermostat cover by replacing its old rubber gasket with a new one.
11. Connect to the negative pole of the battery wire terminal «masses» (-).
12. Set the clock.
13. Enter, if necessary, the code into the radio.
14. Fill in coolant and bleed air from the cooling system.