12 14 600 Removing/replacing Knock Sensors (N52, N52K, N51)

WARNING: This page is about a different variant/trim than selected.

IMPORTANT:

Aluminum-magnesium materials.

No steel screws/bolts may be used due to the threat of electrochemical corrosion.

A magnesium crankcase requires aluminum screws/bolts exclusively.

Aluminum screws/bolts must be replaced each time they are released.

The end faces of aluminum screws/bolts are painted blue for the purposes of reliable identification.

Jointing torque and angle of rotation must be observed without fail (risk of damage) .

Necessary preliminary tasks:

Read out fault memory of DME control unit
Switch off ignition
Disconnect battery negative lead. See 61 20 900 DISCONNECTING AND CONNECTING BATTERY NEGATIVE LEAD
Remove intake air manifold. See 11 61 050 REMOVING AND INSTALLING AIR INTAKE MANIFOLD (N52K)

IMPORTANT: Mixing up the knock sensor plug connections will result in engine damage!
Routing of wires and plug connections must conform to the original routing. This eliminates the risk of confusion and mix-ups.

Release screws on both knock sensors. Remove knock sensors (1).

Installation:

Replace aluminum screws.

Tightening torque 12 14 1AZ. See 12 14 ELECTRONIC SHIFT UNITS OR CONTROL UNITS

Fig 1: Identifying Knock Sensors

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Clean support face of knock sensors on engine block.

NOTE: Check stored fault messages.
Now clear the fault memory.