Removing and installing thermostat Opel Astra H

Tools:

• TORX socket E10
• Sliding pliers

Note:

The need to replace the thermostat may arise when the engine temperature is unstable: overheating or insufficient heating.

To check the thermostat on an Opel Astra car, start a cold engine and touch the upper radiator hose with your hand - it should be cold. After the temperature of the coolant reaches (80 ± 1.5) ° C, the hose should heat up quickly, which indicates the beginning of the circulation of the liquid along the large circuit. If this does not happen, remove the thermostat and check its operation.

On different engines of Opel Astra cars, the thermostat is fixed in different places, but there is a common defining feature: it is always connected to the upper radiator hose. In this subsection, the removal, installation and testing of the thermostat is shown on the example of the Z 16 XER engine.

Removing and installing the thermostat on the Opel Astra N

1. Disconnect a wire from the minus plug of the storage battery.

2. Drain the liquid from the engine cooling system (see Replacing the coolant).

3. Squeeze the clamp of the block of wires of the coolant temperature sensor.

4. Disconnect the ejector block.

5. Loosen the radiator hose clamp with pliers, squeezing its bent ears. 

6. Slide the clamp along the hose and disconnect the hose from the nozzle of the Opel Astra thermostat housing.

7. Turn out 4 bolts of fastening of the case of the thermostat to its module.

Note:

For clarity, shown on the removed cylinder head.

8. Remove the case in gathering with the thermostat.

Note:

The Z 16 XER engine thermostat and its housing are a hard to disassemble unit. When you try to remove the thermostat from the housing, the thermostat mounting posts may break off. Therefore, replace the thermostat assembly with the housing. On other Opel Astra car engines, the thermostat can be easily removed from the housing.

Warning:

If you are installing the old thermostat, use a screwdriver to pry off its rubber seal.

Remove it from the housing flange groove.

Install a new gasket in the groove. If the new thermostat housing does not have a gasket, install a new gasket as well. The old crimped gasket, when reinstalled, may not provide a tight connection.

9. To check, lower the thermostat into a container with water heated to 75-78 ° C.

10. Gradually heating the water, monitor the temperature at which the thermostat valve opens.

Note:

The cooling system thermostat is considered serviceable under the following conditions:

If the thermostat valve does not start to open at a temperature of 90 ° C, then the thermostat on the Opel Astra is faulty and must be replaced.

11. Install all removed parts in the reverse order of removal.

12. Fill in the coolant (see "Changing the coolant").

Source: http://www.automnl.com/model/opel_astra_h2/257/