Removing Cylinder Head
WM 157021 Removing cylinder headPreliminary work
Preliminary work
Information:
If more comprehensive work, e.g. replacement of the entire cylinder head, is intended, the exhaust manifolds must also be removed.
1. Remove engine.
2. Remove cover for camshaft housing.
3. Remove intake-air distributor.
4. Remove chain case lid.
5. Remove camshaft housing.
Information
Component overview
Component overview
1 - Cap
2 - Cylinder head
3 - Straight pin
4 - Pan-head screw M12 x 1.5 x 140
5 - Cap
6 - Spark plug
7 - Cap
8 - Cylinder-head gasket
9 - Vent connection
Removing cylinder head
Removing cylinder head
1. Remove guide rail of timing chain -3-. To do this, unscrew fastening screws -4-.
Timing chain guide rail
1 - Camshaft timing gear
2 - M12 x 140 cheese-head bolt
3 - Guide rails
4 - Guide rail fastening screw
5 - Timing chain; use same running direction when reusing
2. Remove oil separator vent line from cylinder head. To do this, unscrew the fastening screws -3 and upper 4-.
Oil separator vent line from cylinder head.
3. Disconnect vent line for cylinder heads. To do this, press the ribbed surfaces of the buttons and pull off the plugs.
Cylinder head vent line
Information:
In the case of the turbocharged engine (M48/50), only the upper fastening screws of the turbocharger need to be undone.
Turbocharger fastening screws
4. Uncover cable of oxygen sensor front catalytic converter.
5. Unscrew starter catalyst from exhaust manifold. To do this, loosen the 3 fastening nuts.
Fastening nuts for exhaust manifold
6. Unscrew fastening screws of cylinder head in the opposite order of the tightening sequence -figure-.
Illustration shows tightening sequence
Tightening sequence for cylinder head fastening screws
7. Remove cylinder head and cylinder head gasket.