Replacing the Thermostat and/or Engine Coolant Temperature Sensor
Thermostat / temperature sensor, engine coolant, replacingSpecial tools:
951 2885
999 5722
999 7109
951 2953
951 2957
NOTE: The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.
Removing / installing
Removing the engine coolant temperature (ECT) sensor
Remove:
^ the upper timing belt cover. Disconnect the connector for the temperature sensor
^ the temperature sensor from the thermostat housing. Use 951 2885.
NOTE: Put paper underneath the sensor to prevent coolant spillage.
Installing the engine coolant temperature (ECT) sensor
Install:
^ the sensor with a new seal.
Tighten. See: Summary of specific components and tightening torques (Specifications). Use: 951 2885
^ the upper timing belt cover.
Removal
Preparation
Remove the cap from the expansion tank. Install a hose clamp on the upper coolant hose.
The vehicle must be raised for this work. See: Jacking points, body. Remove the lower cover plate.
Position a container under the engine drain cock. Drain 2 liters of engine coolant.
Close the cock. Install the lower protective panel.
Lower the vehicle.
Removing the engine control module (ECM)
Ignition off. Wait for 2 minutes.
CAUTION: Do not touch the terminal pins on the control module with fingers. Static electricity may damage components in the engine control module (ECM).
Remove the cover over the control module box. Put the cover to one side.
Insert tool 999 5722 around the control module.
Move the upper section of the tool backwards as far as it will go. Pull up the tool. Carefully pull up the control module.
For vehicles with automatic transmissions repeat the above work.
Remove the surround from around the control module box.
Removing the auxiliaries belt
NOTE: Make a note of the routing of the belt.
Remove:
^ the auxiliaries belt. Use 999 7109
^ the upper timing belt cover.
Removing the power steering pump
Remove the 3 x screws for the power steering pump. Place the power steering pump to one side.
Removing the thermostat housing
Remove:
^ the hose clamp to the upper radiator hose. Disconnect the hose from the thermostat housing
^ the connector from the temperature sensor
^ the 2 x screws for the thermostat housing at the section against the cylinder head
^ the thermostat housing from the cylinder head
^ the hose clamp for the water hose for heating crankcase ventilation.
Transfer the temperature sensor to the new thermostat housing.
Installation
NOTE: For tightening torques, see: Specifications.
Installing the thermostat housing
Install:
^ the hose for the water heated crankcase ventilation. Before installing the thermostat housing, use a new hose clamp
^ a new gasket
^ the thermostat housing assembly. Tighten the screws
^ the upper radiator hose. Tighten the hose clamp.
Connect the connector for the temperature sensor.
Finishing
NOTE: Ensure that the auxiliaries belt is correctly positioned on all the pulleys.
Install:
^ the power steering pump.
Tighten the 3 x screws
^ the auxiliaries belt. Use 999 7109
^ the upper camshaft cover.
Installing control modules
CAUTION: Check that no pins or sockets are damaged on the connector.
Install the surround for the control module box.
Carefully press the control module down into the grooves on the inside of the control module box. Press to the limit position
Insert tool 999 5722 around the control module.
Move the upper section of the tool forwards as far as it will go. Pull up the tool.
Press the cover into place over the control modules. Check that the air ducts are correctly positioned.
Finishing
Remove the hose clip. Refill with coolant. Use filling equipment 951 2957 and cover 951 2953. Install the cap on the expansion tank. Test drive the engine until the thermostat has opened. Check for leakage. Top-up the coolant.