Removal and Replacement
11 12 100 Removing And Installing Cylinder Head (N55)
Special tools required:
IMPORTANT:
Fit new cylinder head bolts.
Do not wash off bolt coating.
Lightly oil washer on the contact surfaces (both sides).
There must be no coolant, water or engine oil in the blind holes.
Risk of cracking and corrosion.
Necessary preliminary tasks:
- Remove exhaust system.
- Drain coolant.
- Drain engine oil.
- Remove engine.
- Mount engine on assembly stand.
- Remove intake plenum.
- Remove exhaust turbocharger with integrated exhaust manifold.
- Detach coolant hoses from cylinder head.
- Remove intake and exhaust camshaft adjusters.
IMPORTANT: If the timing chain is stowed in the gear case, the crankshaft must no longer be rotated.
Release screws (1).
Unclip timing chain module (2) at separation point (3) and remove towards top.
Set down timing chain.
NOTE: Graphic shows N52.
NOTE: Bolt (2) can only be released when the timing chain module is pressed forward slightly.
Release screws (1).
Tightening torque 11 12 3AZ.
Release screw (2).
Tightening torque 11 12 3AZ.
Release cylinder head bolts in sequence 14 to 11 with special tool 11 4 420.
Release cylinder head bolts in sequence 10 to 1 with special tool 11 8 580.
NOTE: Picture shows intermediate lever and exhaust camshaft removed.
Secure special tool 11 0 320 with bolts (1).
Tightening torque 11 12 4AZ.
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.
NOTE: Graphic shows N52.
Insert 11 4 430 special tool into bore holes.
Remove coarse residues on sealing surfaces with special tool 11 4 471 from cylinder head and crankcase.
IMPORTANT: Do not use any metal-cutting tools.
Remove fine residues on sealing surfaces 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 cracking and corrosion.
Clean all blind holes.
Replace cylinder head gasket.
Fit new cylinder head bolts.
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 intermediate lever and exhaust camshaft removed.
Insert bolts (1).
Tightening torque 11 12 3AZ.
Insert bolt (2).
Tightening torque 11 12 3AZ.
Assemble engine.
