Removal and Replacement
11 12 100 - Removing and installing cylinder head (N54)
Special tools required:
- 11 0 320 11 0 320 Clip
- 11 4 420 11 4 420 Torx
- 11 4 430 11 4 430 Plug
- 11 4 471
- 11 4 472
- 11 8 580 11 8 580 Socket Wrench
Important!
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.
Risk of damage!
Jointing torque and angle of rotation must be observed without fail.
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!
Necessary preliminary tasks:
- Remove engine
- Remove inlet and exhaust adjustment unit Service and Repair
Release screws (1).
Unclip timing chain module (3) at junction (2) 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 Note:
The timing chain is lifted out with a hook only during assembly.
Note:
The lowest screw can only be released when the timing chain module is pressed forward slightly.
Important!
Secure the lowest screw with a gripper against falling down.
Release screws (1).
Tightening torque 11 12 3AZ 11 12 Cylinder Head with Cylinder Head Cover.
Important!
Observe different bolt heads.
Release M9 cylinder head bolts (1) with special tool 11 4 420.
Tightening torque 11 12 2AZ 11 12 Cylinder Head with Cylinder Head Cover.
Release M10 cylinder head bolts (1) with special tool 11 8 580 from outside inwards.
Tightening torque 11 12 1AZ 11 12 Cylinder Head with Cylinder Head Cover.
Important!
All cylinder head bolts must be replaced.
Risk of damage!
Jointing torque and angle of rotation must be observed without fail.
Shims (1) of cylinder head bolts can only be removed with a magnet (2) between cylinder head and bearing strip.
Secure special tool 11 0 320 with existing cylinder head cover bolts (1).
Tightening torque 11 12 4AZ 11 12 Cylinder Head with Cylinder Head Cover.
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 set cylinder head down on sealing face, risk of damage to valves.
Important!
Set down cylinder head with inlet and exhaust camshafts on side only, risk of damage to valves (1).
Insert special tool 11 4 430 into bores.
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.
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.
Installation Note:
Replace cylinder head gasket Service and Repair.
Important!
Observe sequence for tightening cylinder head bolts without fail.
Installation Note:
Fit new cylinder head screws.
Insert cylinder head bolts (1 to 10) with special tool 11 8 580.
Tightening torque 11 12 1AZ. Mechanical Specifications
Insert cylinder head bolts (11 to 14) with special tool 11 4 420.
Tightening torque 11 12 2AZ 11 12 Cylinder Head with Cylinder Head Cover.
Note:
Graphic shows inlet and exhaust camshafts removed.
Observe sequence for tightening cylinder head bolts without fail.
Important!
The 2nd torsion angle relates only to cylinder head bolts 1 to 10.
Installation Note:
- Tightening torque:
All cylinder head bolts 1 to 14 to 30 Nm
- 1st angle of rotation:
All cylinder head bolts 1 to 14 to 90°
- 2nd angle of rotation:
Only cylinder head bolts 1 to 10 to 90°
- 3rd angle of rotation:
All cylinder head bolts 1 to 14 to 45°
Installation Note:
Replace screws (1).
Tightening torque 11 12 3AZ 11 12 Cylinder Head with Cylinder Head Cover.
Important!
Secure the lowest screw with a gripper against falling down.
Assemble engine.