Necessary preliminary work

• Switch off ignition.
• Remove IGNITION COILS  .

Clean spark plug slot with compressed air.

Unscrew the spark plugs with special tool 12 1 171 and an extension with joint.

Installation note: 

First, screw the spark plugs into the engine hand-tight with special tool 12 1 171 and an extension with joint.

Next, tighten the spark plugs with a torque wrench, special tool 12 1 171 and an extension with joint.

Observe tightening torque.

Tightening torque 12 12 2AZ .

Fig 1: Tightening Spark Plugs Using Special Tool (12 1 171)

Courtesy of BMW OF NORTH AMERICA, INC.