Special tools required:
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:
IMPORTANT: Fit new cylinder head screws.
Do not wash off bolt coating.
There must be no coolant, water or engine oil in the pocket holes.
Risk of corrosion and cracking! Release screws (1).
Unclip timing chain module (2) at junction (3) and remove towards top.
Set down timing chain.
IMPORTANT: If the timing chain is stowed in the gearcase, the crankshaft must no longer be rotated.
This would cause the timing chain on the crankshaft sprocket wheel to jam or jump.
Installation:
The timing chain is lifted out with a hook only during assembly.
Fig. 28: Timing Chain Module, Junction And Screws
Release bolts (2) for eccentric shaft sensor (1).
Remove eccentric shaft sensor (1) towards front.
Fig. 29: Removing Eccentric Shaft Sensor
IMPORTANT: Screw (1) is not magnetic and must be secured against falling down.
Release screw (1).
Remove magnet wheel (2) towards front.
Fig. 30: Removing Magnet Wheel
IMPORTANT: Magnet wheel (1) is highly magnetic and must be protected against metal filings/borings.
After removing, place magnet wheel (1) in a plastic bag (2) with a seal.
Fig. 31: Magnet Wheel And Plastic Bag
Pretension eccentric shaft (1) upwards in direction of arrow.
Remove stop screw between 1st and 2nd cylinders.
Tightening torque: 11 37 5AZ.
Fig. 32: Eccentric Shaft
NOTE: Bolt (2) can only be released when the timing chain module is pressed forward slightly.
IMPORTANT: Secure bolt (2) with a gripper against falling down.
Release screw (2).
Tightening torque: 11 12 3AZ.
Release screws (1).
Tightening torque: 11 12 4AZ.
Installation:
Replace aluminium screws.
Fig. 33: Bolt
IMPORTANT: Observe different bolt heads.
Release M10 cylinder head bolts (1) with special tool 11 8 580.
Release M9 cylinder head bolts (2) with special tool 11 4 420.
NOTE: Picture shows inlet and exhaust camshafts removed.
Fig. 34: Special Tools (11 8 580) And (11 4 420)
IMPORTANT: Observe different M9 bolt lengths (1 and 3).
Release M9 cylinder head bolts (1 and 3) with special tool 11 4 420.
Tightening torque: 11 12 2AZ.
Release M10 cylinder head bolts (2) with special tool 11 8 580 from outside inwards.
Tightening torque: 11 12 1AZ.
Fig. 35: Cylinder Head Bolts
IMPORTANT: All cylinder head bolts (1, 2 and 3) must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Risk of damage!
Secure special tool 11 0 320 with existing cylinder head cover bolts (1).
Tightening torque: 11 12 5AZ.
IMPORTANT: Removing and install cylinder head with a second person helping.
Weight of cylinder head with add-on parts is approx. 40 kg.
Do not rest cylinder head on sealing surface. Risk of damage to valves!
Fig. 36: Special Tool (11 0 320)
Insert special tool 11 4 430 into bores.
Fig. 37: Special Tool (11 4 430)
Remove coarse residues on sealing faces with special tool 11 4 471 from cylinder head and crankcase.
IMPORTANT: Do not use any metal-cutting tools.
Fig. 38: Special Tool (11 4 471)
Remove fine residues on sealing faces with special tool 11 4 472 from cylinder head and crankcase.
IMPORTANT: Do not use any metal-cutting tools.
There must be no coolant, water or engine oil in the pocket holes.
Risk of corrosion and cracking! Clean all pocket holes.
Replace cylinder head gasket.
Fig. 39: Special Tool (11 4 472)
IMPORTANT: Observe sequence for tightening cylinder head bolts without fail.
Fit new cylinder head screws.
Insert cylinder head bolts (1 to 10) with special tool 11 8 580.
Tightening torque: 11 12 1AZ.
Insert cylinder head bolts (11 to 14) with special tool 11 4 420.
Tightening torque: 11 12 2AZ.
NOTE: Picture shows inlet and exhaust camshafts removed.
Fig. 40: Cylinder Head Bolts Tightening Sequence
Observe sequence for tightening cylinder head bolts without fail.
IMPORTANT: The 2nd torsion angle relates only to cylinder head bolts 1 to 10.
Installation:
Insert bolts (1).
Tightening torque: 11 12 4AZ.
IMPORTANT: Secure bolt (2) with a gripper against falling down.
Insert bolt (2).
Tightening torque: 11 12 3AZ
Installation:
Replace aluminium screws.
Fig. 41: Bolt
Assemble engine.