11 12 000 Removing and installing/sealing cylinder head cover (N20, N26)

Necessary preliminary tasks: 

• REMOVE bulkhead sound insulation.
• Undo engine wiring harness  in the area of the cylinder head cover. See 12 51 210 REPLACING WIRING HARNESS SECTION FOR IGNITION AND INJECTORS (N20, N26) and 12 51 235 REMOVING AND INSTALLING/REPLACING ENGINE SENSOR SYSTEM WIRING HARNESS MODULE 1 (N20, N26) .
• Remove engine VENTILATION LINE .
• Remove BOTH ACTUATORS .
• Remove and install RAIL .
• Remove HIGH PRESSURE PUMP .
• Remove PRESSURE LINE BETWEEN RAIL AND HIGH PRESSURE PUMP .
• REMOVE feed line.
• Remove VACUUM PUMP .

Unclip oxygen sensor connector (1) from holder and disconnect plug connection.

Fig 1: Oxygen Sensor Connector

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Release screws (1).

Remove flange (2).

Fig 2: Flange And Screws

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Only N20 engine 

Disconnect plug connection (1) from the electro-pneumatic pressure converter (3).

Remove vacuum line (OUT).

Release screws (2) and place pressure converter (3) to one side.

Fig 3: Disconnecting Plug Connection From Electro-Pneumatic Pressure Converter

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Remove cover (2).

Release nut beneath it and set positive battery cable aside.

Tightening torque: 12 42 7AZ .

Fig 4: Pulling Connectors From Power Distribution Module

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Fig 5: Cylinder Head Cover Bolts Tightening/Loosening Sequence (N20)

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Loosen screws of cylinder head cover from outside inwards in 1/2 turns.

Remove cylinder head cover.

Replace all gaskets.

Clean sealing surfaces at the contact surfaces of the cylinder head and the spark plug channels.

Installation note: 

Pay attention when placing cylinder head cover on centering pin (1)

Fig 6: Placing Cylinder Head Cover On Centering Pin

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Fig 7: Cylinder Head Cover Bolts Tightening/Loosening Sequence (N20)

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Fit cylinder head cover.

Insert screws of the cylinder head cover by 1/2 turn.

Tighten the cylinder head cover screws in sequence (1 to 20).

Tightening torque: 11 12 4AZ .