Removing Left/Right Cylinder Head

REPLACING LEFT/RIGHT CYLINDER HEAD GASKET
- Remove Engine, refer to Engine Remove and Install
- Remove upper timing case cover, Remove and Install Upper Timing Case




- Pull off plugs (1 ... 3) on the coolant collector.




- Cut off straps, unscrew nuts and take off the wire harness plate.




- Pull off plug (1).
- Disconnect plug (2).
- Take plugs of engine wire harness (3) out of holders and lay engine wire harness aside




- Unscrew screws and take off holder.




- Loosen hose clamps (1... 3) and take off heater hoses.




- Unscrew nuts and remove heater valve.




- Loosen hose clamps (1 and 2) and remove hose (3).




- Unscrew coolant collector.

Installation Note: Replace gaskets. Check O-ring, replacing if necessary. Coat O-ring with a lubricant to make installation easier.




- Unscrew exhaust pipe.




- Unscrew cylinder head bolts from outside to inside and take off head.

NOTE: Remove remainders of gasket on the cylinder head and crankcase with a gasket remover and hard wood scraper; making sure that gasket remainders are kept out of coolant and oil bores.




- Check levelness of cylinder head and crankcase with a standard steel ruler.




NOTE: Cylinder head gaskets are available in two thicknesses. The gasket must be selected to conform with the maximum piston protrusion of a bank of cylinders. Gaskets are marked with 1 or 2 holes in the rear edge.


Cylinder Head Gaskets:

Maximum Piston Identification of
Protrusion of All Cylinder Head
Six Pistons Gasket Holes
mm (inch)


0.388... 0.610
(0.015 ... 0.024) 1

0.610 ... 0.832
(0.024 ... 0.033) 2




Measuring Piston Protrusion:
- Apply dial gage in Special Tool 00 2 530 on a cleaned cylinder head sealing surface and set gage to zero with preload.




- Apply dial gage on measuring point "A" of a cleaned piston and find the highest point by turning the crankshaft. Note the displayed "piston protrusion A" value.

The mean value of measurements "A" and "B" is the "piston protrusion" of a piston.

- Measure these distances on all six pistons.




Installation Note: Mount the cylinder head gasket with the word "FRONT" facing the timing end of the engine and "TOP" facing up.

NOTE: Gaskets are different for cylinder banks 1...6 or 7...12.

V12 M/S70 Tighten Sequence:

- Mount cylinder head and tighten cylinder head bolts (washed and lubricated with oil) in order of 1 through 14 in two steps.
- Make sure that there is no oil In the holes of the engine block when Inserting bolts (danger of cracking the block!).





- Step 1: Tightening torque: 30 Nm (21.5 ft. lbs.).

NOTE: For hex head bolt, wait 15 minutes for settling.

- Step 2: Torque angle 120° with Special Tool 11 21 10.