12 12 011 Remove and install/replace all spark plugs (N52T)

Special tools required: 

• 12 1 171

Necessary preliminary tasks: 

• Switch off ignition.
• Remove IGNITION COILS .

Clean spark plug slot with compressed air  .

1. Remove dirt contamination from the spark plug shaft. The plug shaft must be cleaned with compressed air after the ignition coils have been removed but before the spark plugs have been dismounted. After removing the spark plugs, check the sealing surface again for dirt contamination and if necessary, clean with a damp cloth or again with compressed air.
   NOTE: Deposits that are not removed according to instructions may enter the combustion chamber and lead to uncontrolled combustion. Remaining deposits in the area of the spark plug seal can lead to leaks and to the spark plugs coming loose during engine operation.
2. Do not grease/oil thread or use any graphite or copper grease. Adhere to the torque values of the packaging information or regulation.
   NOTE: If these instructions are not followed, especially with regard to greasing, this may result in mechanical damage to the spark plug housing/thread. Spark plugs that are not tightened sufficiently lead to leaks and to the spark plugs coming loose during engine operation.

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

Flexible ratchet extensions must always be used. If rigid mounting tools are used, there is a risk of insulator breakages.

Installation note: 

Do not let spark plugs fall into the spark plug shaft. This can lead to a reduction of the electrode gap and so impair the smooth running of the engine, especially in idle mode.

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

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

Observe tightening torque.

Tightening torque 12 12 1AZ .