Knock Sensor: Service and Repair

WM 287220 Removing and installing knock sensors on DFI engines

Technical values





Preliminary work

1. Remove the thermostat housing for the two front knock sensors. -> 195519 Removing and installing housing for coolant regulator (thermostat housing) on 4.8-litre DFI engines Service and Repair
2. Remove the starter for the two rear knock sensors. -> 276019 Removing and installing starter 276019 Removing and Installing Starter

Removing knock sensors

1. Observe and note installation position of knock sensors. Pull off cable plug. => Pulling off cable plug





Pulling off cable plug

2. Unscrew fastening screw and take knock sensor out of the crankcase.





Knock sensors






Installing knock sensors

Information

- Clean contact surface of knock sensor with a cloth.

CAUTION

Engine damage and changed exhaust behaviour due to incorrectly mounted knock sensors.

-> The precise tightening torque for the knock-sensor screw must be observed, otherwise the proper function of the knock sensor is not ensured.
-> The knock sensors must a aligned so that the sensor housing and the cable plug do not touch anywhere, otherwise proper functioning of the knock sensor is not ensured.

1. Install knock sensors. Make sure that the knock sensors are aligned as shown in the illustration.





Knock sensors





2. Tighten fastening screws.
3. Push on cable plug.

Subsequent work

1. Fit the thermostat housing for the two front knock sensors. -> 195519 Removing and installing housing for coolant regulator (thermostat housing) on 4.8-litre DFI engines Service and Repair
2. Fit the starter for the two rear knock sensors. -> 276019 Removing and installing starter 276019 Removing and Installing Starter