Information on cylinder head contact surface - AH01.30-P-1000-05A
WARNING: This page does not describe the selected car, but rather 28 other vehicles, including the 2012 Mercedes-Benz GL550, 2012 Mercedes-Benz GL450, 2011 Mercedes-Benz ML63, 2011 Mercedes-Benz ML550, and 2011 Mercedes-Benz ML350. However, it is still accessible from the selected car via links, so may be relevant.
Engine 112, 113
The cylinder head contact surface must only be machined if mechanically damaged points are present.
The cylinder head contact surface must not be re-worked (face-ground) if a variation exists in the flatness of the cylinder head contact surface in the longitudinal direction and transverse direction (distortion).
When the cylinder head is fitted on again, the distortion is compensated for by tightening the cylinder head bolts.
Stock removal on the cylinder head and at the crankcase of an engine must together be not more than 0.3 mm.
The valve seats must be re-set if the cylinder head separating surface is machined.