Thermostat Installation Details
Details of the thermostat installation on models with gasoline engines of the M104.94 / 99 series; thermostat is installed with a ball valve (indicated by an arrow on the callout) up.
1 - Thermostat; 2 - Seal; 3 - Thermostat cover; 4 - Bolts; 5 - Bracket
Thermostat installation details on models with 119.97/98 series petrol engines
1 - Branch pipe; 2 - Cover; 3 - O-ring; 4 - Thermostat; 5 - Dipstick for measuring the level of impellent oil
Thermostat installation details on models with 120.980/982 series petrol engines
1, 2 - Branch pipes; 3 - Thermostat housing cover; 4, 5 - Temperature sensors; 4a, 5a - Oil seals; 6 - Bracket; 7 - Thermostat; 7a - Profile plate; 8 - O-ring; 10, 11 - Bolts
Details of thermostat installation on models with diesel engines
17 - Thermostat housing; 19 - O-ring; 20 - Thermostat
Removing
1. Disconnect the ground cable from the battery.
2. Empty the cooling system (see chapter Current service). If you are not going to add new fluid to the system, save the drained fluid for later use.
3. Disconnect from the case of the thermostat a branch pipe.
4. Remove thermostat cover/housing.
5. Remove the thermostat from the housing - try to remember the location of the air bleed ball valve and the orientation of the thermostat itself.
Installation
Installation is carried out in the reverse order of removal. Don't forget to replace the o-ring.
Note. The thermostat is installed with the bleed valve upwards.