Removal
1. Disconnect the ground cable from the battery (see "Disconnecting the battery").
2. On 1.9L DW series diesel engines, release the clamp in the center of the engine cover and remove the screw on the right side. Remove the engine cover. On 2.0L diesel engines, rotate the four plastic fasteners 90° and remove the engine cover (Figure 4.2, a-d).
Figure 4.2, a. On 1.9L diesel engines, remove the fasteners on the right side...
Figure 4.2, b....and on the upper plane of the engine cover
Figure 4.2, c....then remove the engine cover
Figure 4.2, d. On 2.0L diesel engines, to release each lock, turn it 90°...
Figure 4.2, d....and then remove the engine cover
(Original published on the portal peugeotbook.ru)
3. Drain the coolant from the cooling system (see chapter 1A or 1B).
4. Remove the air cleaner assembly and air intake ducts as described in the chapter 4A, 4B or 4B.
5. Loosen the bolts and carefully remove the thermostat housing cover to expose the thermostat (figure 4.5). Be careful not to deform the coolant hose connected to the cap. Keep in mind that the thermostat housing design varies depending on the engine type, but the thermostat removal technique is the same for each type.
Figure 4.5. Location of the cover on the thermostat housing (marked with an arrow) (model with a 1.4 L petrol engine)
6. On early models with a separate thermostat, remove the thermostat from the housing, noting how it is installed. Remove the sealing ring (figure 4.6).
Figure 4.6. Removing the sealing ring from the thermostat flange
7. On later models where the thermostat is an integral part of the housing cover, remove the O-ring, release the clamp and remove the cover from the coolant hose.
Examination
8. A rough test of the thermostat can be done by hanging it on a piece of fishing line in a container filled with water. Heat the water until it comes to a boil. The thermostat should open by the time the water boils. If this is not the case, replace it.
9. If you have a thermometer, you can determine the exact temperature at which the thermostat opens. Compare this value with the opening temperature specified in "Specifications". The opening temperature should also be indicated on the thermostat.
10. A thermostat that does not close as the water cools must be replaced.
Installation
11. Installation is carried out in the reverse order of removal, taking into account the following points: