Knock Sensor: Service and Repair

WM 287219 Removing and installing knock sensor

Technical values





Preliminary work

DANGER

Vehicle can fall down

- Risk of squashing or crushing
- Risk of damage to the vehicle

-> Do not place any solid objects under the raised vehicle.
-> Ensure that the lifting platform is prevented from lowering.
-> Remove solid objects before lowering the vehicle.
-> Raise the vehicle only at the take-up points provided.
-> The outer take-up points should be used primarily.

1. Raise the vehicle.
-> 4X00IN01 Lifting the vehicle
2. Place protective covers on the vehicle to avoid damaging the body and passenger compartment.
3. Remove air cleaner housing.
-> 242519 Removing and installing air cleaner housing - section on "Removing" Service and Repair.

Removing knock sensor

Removing knock sensor for cylinder bank 1-3

1. Disconnect the battery.
-> 2706IN00 Work instructions after disconnecting the battery
2. Remove the generator.
-> 272219 Removing and installing generator - section on "Removing" Service and Repair.
3. Pull off tank vent line.





Tank vent

3.1. Unclip line at the resonance tube -arrow- and feed line for the carbon canister -1- and set them aside.
3.2. Pull tank vent out of the bracket -2-.

Information

Before removing the knock sensor, mark the installation position using a water-resistant marker.

4. Remove knock sensor for cylinder bank 1-3.





Knock sensor for cylinder bank 1-3

4.1. Release and pull off cable plug -3-.
4.2. Unscrew external Torx screw (M8 x 35) -4- for the knock sensor and remove the knock sensor.

Removing knock sensor for cylinder bank 4-6

1. Remove resonance tube.

-> 247419 Removing and installing resonance tube
2. Remove intake-air distributor pipe on cylinder bank 4-6.
-> 244619 Removing and installing intake-air distributor
3. Remove holder for fuel high-pressure connecting line.





Fuel line holder

3.1. Unscrew external Torx screw (M6 x 16) -3- on the holder.
3.2. Loosen external Torx screw M6 x 12 -2- on the holding clamp.
3.3. Slide holder -1- to one side.

Information

Before removing the knock sensor, mark the installation position using a water-resistant marker.

4. Remove knock sensor for cylinder bank 4-6.





Knock sensor for cylinder bank 4-6

4.1. Release and pull off cable plug -2- on the knock sensor.
4.2. Unscrew external Torx screw (M8 x 35) -3- on the knock sensor.
4.3. Remove knock sensor -1-.

Installing knock sensor

Installing knock sensor for cylinder bank 1-3

1. Install knock sensor for cylinder bank 1-3.





Knock sensor for cylinder bank 1-3

1.1. Clean sealing surface of knock sensor with a cloth.
1.2. Screw in and tighten external Torx screw (M8 x 35) -4- on the knock sensor.
The precise tightening torque for the knock-sensor screw must be observed, otherwise the knock sensor might not function properly.
=> Tightening torque: 23 Nm (17 ftlb.)
1.3. Connect and lock cable plug -3-.
2. Install tank vent line.





Tank vent

2.1. Insert tank vent into the holder -2- and press firmly.
2.2. Clip in line at the resonance tube -arrow- and the feed line for the carbon canister -1-.
The plug-in couplings must lock with an audible click.
3. Connect the battery.
-> 2706IN00 Work instructions after disconnecting the battery.
4. Install the generator.
-> 272219 Removing and installing generator.

Installing knock sensor for cylinder bank 4-6

1. Install knock sensor for cylinder bank 4-6.





Knock sensor for cylinder bank 4-6

1.1. Clean contact surface of knock sensor with a cloth.
1.2. Fit knock sensor -1-.
1.3. Screw in and tighten external Torx screw (M8 x 35) -3- on the knock sensor.
The precise tightening torque for the knock-sensor screw must be observed, otherwise the knock sensor might not function properly.
=> Tightening torque: 23 Nm (17 ftlb.)
1.4. Push on cable plug -2-.
2. Install holder for fuel high-pressure connecting line.





Fuel line holder

2.1. Slide holder -1- and holding clamp into installation position.
2.2. Tighten external Torx screw M6 x 12 -2- on the holding clamp.
=> Tightening torque: 10 Nm (7.5 ftlb.)
2.3. Screw in and tighten external Torx screw (M6 x 16) -3- on the holder.
=> Tightening torque: 10 Nm (7.5 ftlb.)
3. Install resonance tube.
-> 247419 Removing and installing resonance tube - section on "Installing" Service and Repair.
4. Install intake-air distributor pipe on cylinder bank 4-6.
-> 244619 Removing and installing intake-air distributor - section on "Installing" 244619 Removing and installing intake-air distributor.

Subsequent work

1. Install air cleaner housing.
-> 242519 Removing and installing air cleaner housing - section on "Installing" Service and Repair.