12 14 600 Replace the knock sensor (N12, N14, N16, N18)

Necessary preliminary work: 

• Switch off ignition.
• Read out fault memory of DME control unit.
• Disconnect NEGATIVE BATTERY CABLE .
• Check stored fault messages.
• All-wheel drive vehicles only: Remove intake plenum.

Installation location:

The knock sensor is located under the intake air manifold next to the starter motor.

Use a reversible ratchet (1) and extension to release the screw of the knock sensor from below.

Fig 1: Releasing Knock Sensor Screw Using Reversible Ratchet

Courtesy of BMW OF NORTH AMERICA, INC.

Release screw and remove knock sensor (2).

Pull knock sensor slightly downwards until the connector of the knock sensor is accessible. Unlock connector (1) and remove.

Installation note: 

Clean contact surface of knock sensor on engine block.

Tightening torque 13 62 2AZ .

Fig 2: Identifying Connector And Screw

Courtesy of BMW OF NORTH AMERICA, INC.