12 14 600 Removing/replacing knock sensors (N52, N52K, N51)

IMPORTANT: Aluminium-magnesium materials.

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

A magnesium crankcase requires aluminium screws/bolts exclusively.

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

The end faces of aluminium 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:

Unlock plug (1) and remove.

Fig 1: Identifying Knock Sensor Plug

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws on both knock sensors (1) and remove knock sensors (1).

Installation:

Replace aluminium screws.

For tightening torque refer to 12 14 1AZ in 12 14 ELECTRONIC SHIFT UNITS OR CONTROL UNITS .

Fig 2: Locating Knock Sensors Screws

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Installation:

Clean support face of knock sensors on engine block.

Fig 3: Identifying Knock Sensors Support Face And Cleaning Procedure On Engine Block

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NOTE: Check stored fault messages.

Now clear the fault memory.