Examining, tightening cylinder head bolts - RA01001044050X(01-4050)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Cylinder Head Bolts Length

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

EXAMINING

Length (L) of cylinder head bolts

examine.

NOTE: The cylinder head bolts are subjected to a certain stretch each time they are tightened. If the maximum length (L) is exceeded, the bolts should be replaced.

TIGHTENING

Threads of cylinder head bolts and threaded holes in crankcase	clean. Fluids forced into the threaded holes may damage the crankcase.
Threads of cylinder head bolts and contact surfaces of washers	oil with engine oil.
Cylinder head bolts	tighten in stages in the order of the tightening diagram, starting with 1.
	1st stage	55 Nm
	2nd stage	90° tightening angle
	3rd stage	90° tightening angle
	The cylinder head gasket is not watertight until the engine has reached its normal operating temperature and the gasket has swollen. For this reason, do not pressure-test the cooling system until the engine has reached normal operating temperature.

TIGHTENING TORQUES IN NM

Cylinder head bolts, engine cold

1st stage
2nd stage 90° tightening angle
3rd stage 90° tightening angle

LENGTH OF CYLINDER HEAD BOLT IN MM

Length (L) when new	Maximum length (L)
160	163.5 mm

Special tool

Fig 2: Identifying Special Tool (617 589 00 10 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.