Comment. When installing the thermostat, replace the O-ring and gasket.
Withdrawal
1. Disconnect the negative cable from the battery.
2. Drain the coolant as described in chapter 1.
N42 engine
3. Remove the wire clamp and disconnect the lower hose from the thermostat (pic. 4.3). Disconnect the thermostat electrical connector (if any).
4. Remove the thermostat cover together with the thermostat itself by unscrewing the screws securing the cover (pic. 4.4). The thermostat is made integral with the cover and only their assembly can be replaced. The o-ring can be discarded - a new one will be required during assembly.
M43TU engine and 6-cylinder engines
5. To access the thermostat, remove the cooling fan and viscous coupling as directed in chapter 3.
6. Disconnect the hoses from the thermostat. On models with electrically heated thermostat, disconnect the electrical connector from the thermostat.
7. Remove the thermostat housing by unscrewing the screws securing it (pic. 4.7), Remove the gasket under the thermostat. On a 6-cylinder engine, to remove the thermostat housing, you must first remove the lifting eye from the cylinder head.
8. The thermostat is integral with the housing. Remove the O-ring (pic. 4.8).
Installation
9. Establish the thermostat in sequence, return to removal, taking into account the following remarks.
- A) Replace thermostat o-ring.
- b) Tighten the thermostat fixing screws to the required torque.
- V) On 6-cylinder models, install a cooling fan.
- G) Finally, fill the cooling system.