Removal and Replacement

11 12 100 Removing and Installing/Replacing Cylinder Head (M52TU / M54 / M56)

Special tools required:
- 00 0 200
- 00 9 120

Remove both exhaust manifolds Exhaust Manifold

Note:
After removing exhaust manifolds:
Reinstall engine support arm with engine mount and remove special tool 00 0 200

Remove intake filter housing with air-mass flow sensor. Air Flow Meter/Sensor
Remove cylinder head cover Valve Cover
Remove all spark plugs. Spark Plug
Remove intake air manifold Intake Manifold

Remove coolant drain plug in engine block.
Drain and dispose of coolant.

Installation:
Replace sealing ring on drain plug.
Tightening torque: 25 Nm
Vent cooling system and check for leaks Bleeding Cooling System

Remove coolant thermostat housing. Service and Repair





Remove coolant pipe.

Note: If the coolant pipe cannot be fed out:
Release banjo bolt (1) and disconnect oil pressure line for VANOS adjustment unit.

Installation:
Replace O-ring on coolant pipe.
If necessary, replace sealing rings on banjo bolt (1).
Tightening torque of banjo bolt (1): 32 Nm

Removal
Removal of cylinder head is described separately from installation.
Remove double VANOS adjustment unit Service and Repair
Remove camshafts with bearing strips Service and Repair





Release screw connection between timing case cover and cylinder head.





Release screws, remove chain guide.





Release cylinder head bolts from outside to inside in sequence 14 to 1.
Lift off cylinder head.

Installation
Installation of cylinder head is described separately from removal.

Clean sealing faces of cylinder head and engine block; if necessary, remove traces of gasket with hardwood spatula. Make sure no gasket remnants drop into oil and cooling channels.





Check dowel sleeves for damage and correct installation position.
Apply permanently elastic sealing compound Drei Bond 1209 to joints to timing case cover.
Replace cylinder head gasket.





Note: A cylinder head seal 0.3 mm thicker than usual can be obtained for machined (milled) cylinder heads.

Caution:
Different cylinder head bolts for M52TU engine:
M10 x 95 for engines with cast iron engine block.
M10 x 110 for engines with aluminum engine block.

Use cylinder head bolts only once.
There must be no oil in the tapped holes of the engine block and the timing case cover.
Risk of cracking and distorted tightening values.





Put the cylinder head on.
Apply a light coat of oil to washer contact area and thread of new cylinder head bolts.
Tighten down cylinder head bolts in sequence 1 to 14.
Replace, wash and oil screws
Jointing torque: 30 Nm
Torque angle: 90°
Torque angle: 90°

Note: Use special tool 00 9 120 for torsion angle tightening.





Install chain guide.





Insert screws and tighten down screw connection between timing case cover and cylinder head.
Install camshafts. Service and Repair
Install double VANOS adjustment unit. Service and Repair
Assemble engine.