Thermostat: Service and Repair

Removing and installing coolant regulator (thermostat)

Tools





Preliminary work





1. Drain cooling system.
2. Remove intake-air distributor.

Information

Component overview











Removing thermostat





1. Remove the two coolant lines on the thermostat housing cover. To do this, remove the spring-band clamps and pull off the hoses.





2. Pull off the cable duct upwards over the coolant pump.
3. Release the upper fastening screw of the oil dipstick.





4. Loosen the fastening screw on the cable duct.





5. Disconnect the coolant outlet on the generator. To do this, open the spring-band clamps and pull off the hose. Collect the draining coolant.





6. Remove the coolant return line on the thermostat housing. To do this, loosen the fastening screw and pull off the line.





7. Disconnect vent line for cylinder heads. To do this, press the ribbed surfaces of the buttons and pull off the plugs.





8. Undo the 3 rear fastening screws of the heater pipes.
9. Undo the thermostat housing cover. The sequence shown must be observed when doing so.








10. Lift the housing cover. Remove the thermostat using assembly aid 9627.

Installing thermostat

Note: All seals between opened sealing surfaces must be replaced.








1. Insert thermostat in the cover and turn it until the two sheetmetal edges are lying to the left and right of the holder.
2. Replace inner and outer seal in thermostat housing cover.
3. Position thermostat housing cover and tighten the fastening screws (M6 x 25) according to the sequence shown. Tightening torque: 7.5 ft-lb.








4. Tighten the three rear fastening screws (M6 x 16) on the heater pipes. Tightening torque: 7.5 ft-lb.





5. Connect vent lines for cylinder heads. The connectors must engage audibly.





6. Fit coolant line leading to the generator. Insert the line in the thermostat housing cover and tighten the fastening screw. Tightening torque: 7.5 ft-lb.





7. Push coolant line onto generator and fit the spring-band clamp.





8. Push the holder onto the timing case cover below the cable duct and tighten the fastening screw. Tightening torque: 7.5 ft-lb.





9. Tighten the upper fastening screw of the oil dipstick. Tightening torque: 7.5 ft-lb.





10. Push the cable duct onto the retaining bracket over the coolant pump.
11. Check whether the drive belt is correctly installed.





12. Fit coolant supply and return hose on thermostat housing cover.

Subsequent work

1. Install intake distributor.
2. Fill coolant system and check for leaks.