Cylinder Head
Removing and installing cylinder head
Preliminary work
Notice
Dirt and contamination
- Risk of damage to units or components
- Protect components from dirt and contamination.
- Clean or replace dirty components.
1. Remove cylinder head cover.
2. Remove camshafts.
Removal
Removing cylinder head
Notice
Dirt and contamination
- Risk of damage to units or components
- Protect components from dirt and contamination.
- Clean or replace dirty components.
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E..) for external Torx, (T..) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
Component overview
Cylinder head, bank 4-6
1 - External Torx screw, M6 x 25
2 - External Torx screw, M6 x 80
3 - Internal Torx screw, M12 x 1.5 x 140
4 - External Torx screw, M12 x 1.5 x 140
Information
- Position hydraulic tappets on a surface you have prepared and labelled yourself in accordance with their installation position in the cylinder head.
- Components have been run in in fitted bores and must not be confused.
- Do not use magnets for removal or installation. This can cause the components to malfunction.
1. Remove hydraulic tappets.
1.1. Pull six bucket tappets -1- and six switching tappets -2- out of the fitted bores in the cylinder head. Do not use magnets.
Hydraulic tappets for valve control
1.2. Lay components on clean, labelled cardboard.
Example of laying aside bucket tappets
1.3. If you see any sign of wear, replace the affected hydraulic tappet.
To remove cylinder head 1-3:
2. Remove two bearing pins on the cylinder head - one at the top for the guide rail -1- and one at the bottom for the tensioning rail -2-.
Bearing pins on cylinder bank 1-3
2.1. Replace O-rings.
3. Unscrew three external Torx screws (E10, M6 x 25) -1- on the outside of the cylinder head.
Screws on outside of cylinder head 1-3
3.1. Unscrew four external Torx screws (E10) - three M6 x 25 screws -1- and one M6 x 80 screw -2- - on the inside of the cylinder head.
Overview of screws for cylinder head 1-3
3.2. Loosen two external Torx screws (M12 x 140) -3- and six internal Torx screws (M12 x 140) -4- from the outside in and unscrew them.
To remove cylinder head 4-6:
4. Pull off oil supply valve for vacuum pump -1- and remove bearing pin for guide rail on the cylinder head -2-.
Bearing pins on cylinder bank 4-6
4.1. Replace O-rings.
5. Unscrew two external Torx screws (E10, M6 x 25) -1- on the outside of the cylinder head.
Screws on outside of cylinder head 4-6
5.1. Unscrew four external Torx screws (E10) - three M6 x 25 screws -1- and one M6 x 80 screw -2- - on the inside of the cylinder head.
Overview of screws for cylinder head 4-6
5.2. Loosen two external Torx screws (M12 x 140) -3- and six internal Torx screws (M12 x 140) -4- from the outside in and unscrew them.
6. Lift off cylinder head.
6.1. Check the fitted bores of the hydraulic tappets for signs of wear. If you see signs of wear, the cylinder head and any worn tappets must be replaced.
6.2. Check the sealing face for signs of distortion and wear before re-installation and carry out approved repairs if necessary.
7. Remove and dispose of cylinder head gasket -1-. Check dowel sleeves -2- for signs of damage and replace if necessary.
Cylinder head gasket
8. If you need to disassemble the cylinder head further, remove the displacement bodies -1- on cylinder bank 1-3 using flat-nosed pliers.
Marking pistons
Installation
Installing cylinder head
Notice
Dirt and contamination
- Risk of damage to units or components
- Protect components from dirt and contamination.
- Clean or replace dirty components.
Information
- Position hydraulic tappets on a surface you have prepared and labelled yourself in accordance with their installation position in the cylinder head.
- Components have been run in in fitted bores and must not be confused.
- Do not use magnets for removal or installation. This can cause the components to malfunction.
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E..) for external Torx, (T..) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
Component overview
Cylinder head, bank 4-6
1 - External Torx screw, M6 x 25
2 - External Torx screw, M6 x 80
3 - Cylinder-head screw, internal Torx M12 x 1.5 x 140
4 - Cylinder-head screw, external Torx M12 x 1.5 x 140
1. Make sure that the twelve displacement bodies -1- are in place on cylinder bank 1-3.
Marking pistons
2. Fit a new cylinder-head gasket. Check that the dowel sleeves are installed correctly.
3. Carefully place cylinder head in position.
Information
- The tightening sequence must be strictly observed.
4. Fit two external Torx screws (M12 x 140) and six internal Torx screws (M12 x 140) and tighten according to tightening specifications.
Tightening sequence for cylinder head screws
5. Screw in four external Torx screws (E10) - three M6 x 25 screws -1- and one M6 x 80 screw -2- - on the inside of the cylinder head and tighten according to specifications.
- Tightening torque: 13 Nm (9.5 ft lb.)
Overview of screws for cylinder head 1-3
Overview of screws for cylinder head 4-6
6. Screw in external Torx screws (E10, M6 x 25) on the outside of the cylinder head and tighten according to specifications.
- Tightening torque: 13 Nm (9.5 ft lb.)
7. Coat hydraulic tappets with new engine oil and guide into original installation position.
7.1. Installation position of switching tappets -1- (intake side) and dowel pin -2-.
Position of switching tappets
7.2. Installation position of switching tappets -1- (outlet side) and dowel pins -2-.
Position of bucket tappets
Subsequent work
1. Install camshafts.
2. Install cylinder head cover.