Necessary preliminary tasks

• Remove CYLINDER HEAD COVER 
• Check TIMING 

Fit special tool 11 4 283 with screws (1).

Fit special tool 11 4 281 on special tool 11 4 283.

Fig 1: Releasing Cylinder Head Bolt

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Release chain tensioner (2).

Tightening torque 11 31 6AZ .

Release central bolts on inlet and exhaust adjustment units (1).

Tightening torque 11 36 1AZ .

Installation: 

Replace central bolts. 

Fig 2: Identifying Inlet/Exhaust Adjustment Units And Chain Tensioner

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Remove exhaust adjustment unit (1) from exhaust camshaft.

Remove inlet adjustment unit (2) from inlet camshaft.

Installation: 

To facilitate removal and installation of the inlet and exhaust adjustment units, turn the sensor gears at the opening downwards.

Fig 3: Removing Exhaust Adjustment Unit From Exhaust Camshaft

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Inlet and exhaust adjustment units are different.

VANOS is marked with AUS/EX for the exhaust camshaft.

VANOS is marked with EIN/IN for the inlet camshaft.

Sensor gears can be fitted alternatively.

Fig 4: Identifying Marking On Exhaust And Inlet Camshaft

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Position inlet and exhaust adjustment units on camshafts.

Installation position of inlet and exhaust adjustment units can be freely selected.

Insert central bolts (1).

Tightening torque 11 36 1AZ .

Installation: 

Replace central bolts. 

Fig 5: Identifying Central Bolts

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Press clamping rail (1) by hand against guide rail and make sure timing chain is guided in clamping rail (1).

Adjust VALVE TIMING .

Fit CHAIN TENSIONER .

Fig 6: Identifying Clamping Rail

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Assemble engine.