12 12 011 Replacing all spark plugs (M73)

Switch off ignition.

Cylinder bank 1-6:

Press interlock (2) and remove connector (1).

Fig 1: Removing Connector (Cylinder Bank 1-6)

Open clips (1).

Unfasten hose clip (2) from auxiliary hose for air pump.

Disconnect plug-in connection (3).

Unfasten hose clip (4).

Remove upper section of suction filter housing with mass air flow sensor.

Fig 2: Removing Suction Filter Housing Upper Section With Mass Air Flow Sensor

Cylinder bank 7-12:

Open clips (1).

Unfasten hose clip (2).

Disconnect plug-in connection (3).

Remove upper section of suction filter housing with mass air flow sensor.

Fig 3: Removing Suction Filter Housing Upper Section With Mass Air Flow Sensor (Cylinder Bank 7-12)

Disconnect plug connections (1 and 2) from heating valve.

Fig 4: Disconnecting Heating Valve Connector

Pull heating valves (1) out of rubber mounts (2) and lay below engine.

Fig 5: Removing Heating Valves From Rubber Mounts

Release cable ties (1) and lay air hose (2) below engine.

Fig 6: Releasing Cable Ties

Cylinder 1 -8

Use special tool 12 7 131 (extension) and special tool 12 1 171.

Fig 7: Identifying Special Tool (Cylinder bank 1-8) (1 Of 2)

Cylinder 1 -8

Installation:

Tighten down spark plug with special tool 12 1 171 and special tool 12 7 131 (extension), special tool 12 1 200 (torque limiter). Without special tool 12 1 200, note Tightening torque.
Tightening torque, refer to TORQUE SPECIFICATIONS .

Fig 8: Identifying Special Tool (Cylinder bank 1-8) (2 Of 2)

Cylinder 9-12

Use special tool 12 7 132 (extension) and special tool 12 1 171.

Fig 9: Identifying Special Tool (Cylinder bank 9-12) (1 Of 2)

Cylinder 9-12

Installation:

Tighten down spark plug with special tool 12 1 171 and special tool 12 7 132 (extension), special tool 12 1 200 (torque limiter). Without special tool 12 1 200, note Tightening torque.
Tightening torque, refer to TORQUE SPECIFICATIONS

Fig 10: Identifying Special Tool (Cylinder bank 9-12) (2 Of 2)