Cylinder Head Assembly: Service and Repair
WM 157019 Removing and installing cylinder head
Technical values
Preliminary work
Preliminary work for cylinder head 1-3
NOTICE
Dirt and contamination
- Risk of damage to units or components
-> Protect components from dirt and contamination.
-> Clean or replace dirty components.
Information
- Always replace O-rings.
- Moulded seals can be reused and are only replaced if damaged.
1. Remove the engine.
-> 100119 Removing and installing engine 100119 Removing and installing engine.
2. Loosen three external Torx screws (E12, M8 x 12) on the hydraulic pump pulley (do not unscrew fully).
3. Release drive belt.
-> 137819 Removing and installing drive belt Service and Repair.
4. Remove hydraulic pump pulley.
4.1. Unscrew three external Torx screws (E12, M8 x 12) and remove pulley.
5. Completely remove intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
6. Disconnect fuel connection line.
-> 249019 Removing and installing fuel connection line .
7. Remove the generator.
-> 272219 Removing and installing generator Service and Repair.
8. Pull off positive crankcase ventilation line on the cylinder head cover.
9. Loosen air conditioning compressor.
-> 873419 Removing and installing air conditioning compressor Service and Repair.
10. Disconnect hydraulic pump for power steering.
-> 489819 Removing and installing hydraulic pump - as of model year 2009 Service and Repair.
11. Remove fuel collection pipe with fuel injectors if necessary (not required after replacing cylinder head gasket).
-> 243019 Removing and installing fuel collection pipe (with fuel injectors) Service and Repair.
12. Remove coolant regulator housing cover with coolant regulator.
-> 195519 Removing and installing coolant regulator cover 195519 Removing and installing coolant regulator cover.
13. 3.4-litre DFI engine only: Remove high-pressure pump.
-> 246319 Removing and installing high-pressure pump .
14. Remove housing for coolant regulator.
-> 195519 Removing and installing housing for coolant regulator 195519 Removing and installing housing for coolant regulator.
15. Remove coolant distributor housing (unit carrier).
-> 195919 Removing and installing coolant distributor housing (unit carrier) - Engine installed 195919 Removing and installing coolant distributor housing (unit carrier) - Engine installed.
16. Remove cylinder head cover.
-> 158219 Removing and installing cylinder head cover Service and Repair.
17. Remove positive crankcase ventilation cover.
Positive crankcase ventilation cover 1-3
18. 2.9-litre SRE engine only: Remove plastic cap.
Cap on cylinder head
19. Remove camshafts.
-> 150520 Removing and installing camshafts (includes setting timing) Service and Repair.
Preliminary work for cylinder head 4-6
1. Remove the engine.
-> 100119 Removing and installing engine 100119 Removing and installing engine.
2. Completely remove intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
3. Remove hydraulic return line for power steering from the oil/water heat exchanger and pull it out of the holder.
4. Pull off positive crankcase ventilation line.
5. Remove positive crankcase ventilation cover on the cylinder head.
Positive crankcase ventilation cover 4-6
6. Remove vacuum pump.
-> 477619 Removing and installing vacuum pump - as of model year 2009 Service and Repair.
7. Remove cylinder head cover.
-> 158219 Removing and installing cylinder head cover Service and Repair.
8. Remove camshafts.
-> 150520 Removing and installing camshafts (includes setting timing) Service and Repair.
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
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 and cover them.
Example of laying aside bucket tappets
1.3. If you see any sign of wear, replace the affected hydraulic tappet.
1.4. Do not clean the hydraulic tappets in a washer. Only wash the outside if necessary.
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.
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.
Overview of screws for cylinder head 4-6
6. Lift off cylinder head. Get another person to help if necessary.
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-.
7.1. 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
9. Clean components, sealing faces and connections.
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. Make sure that the twelve displacement bodies 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 ftlb.)
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 ftlb.)
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 bucket tappets -1- (outlet side) and dowel pins -2-.
Position of bucket tappets
Subsequent work
Subsequent work for cylinder head 1-3
1. Install camshafts.
-> 150520 Removing and installing camshafts (includes setting timing) Service and Repair.
2. Install cylinder head cover.
-> 158219 Removing and installing cylinder head cover - engine removed Service and Repair.
3. 2.9-litre SRE engine only: Fit new plastic cap while dry onto the cylinder head (belt side).
4. Install positive crankcase ventilation cover.
Positive crankcase ventilation cover 1-3
5. Install housing for coolant regulator.
-> 195519 Removing and installing housing for coolant regulator 195519 Removing and installing housing for coolant regulator.
6. Install coolant distributor housing (unit carrier).
-> 195919 Removing and installing coolant distributor housing (unit carrier) - Engine installed 195919 Removing and installing coolant distributor housing (unit carrier) - Engine installed.
7. 3.4-litre DFI engine only: Install high-pressure pump.
-> 246319 Removing and installing high-pressure pump .
8. Install coolant regulator housing cover with coolant regulator.
-> 195519 Removing and installing coolant regulator cover 195519 Removing and installing coolant regulator cover.
9. Install fuel collection pipe with fuel injectors if necessary (not after replacing cylinder head gasket).
-> 243019 Removing and installing fuel collection pipe (with fuel injectors) Service and Repair.
10. Fit hydraulic pump for power steering.
-> 489819 Removing and installing hydraulic pump - as of model year 2009 Service and Repair.
11. Fit air conditioning compressor.
-> 873419 Removing and installing air conditioning compressor Service and Repair.
12. Pull off positive crankcase ventilation line on the cylinder head cover.
13. Fit fuel connection line.
-> 249019 Removing and installing fuel connection line .
14. Install the generator.
-> 272219 Removing and installing generator Service and Repair.
15. Completely install intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
16. Install hydraulic pump pulley.
16.1. Fit three external Torx screws (E12, M8 x 12) and tighten hand-tight.
17. Fit and tension the drive belt.
-> 137819 Removing and installing drive belt Service and Repair.
18. Secure pulley for hydraulic pump.
18.1. Tighten three external Torx screws (E10, M8 x 12) on the hydraulic pump pulley.
=> Tightening torque: 23 Nm (17 ftlb.)
19. Install the engine.
-> 100119 Removing and installing engine 100119 Removing and installing engine.
Subsequent work for cylinder head 4-6
1. Install camshafts.
-> 150520 Removing and installing camshafts (includes setting timing) Service and Repair.
2. Install cylinder head cover.
-> 158219 Removing and installing cylinder head cover Service and Repair.
3. Install vacuum pump.
-> 477619 Removing and installing vacuum pump - as of model year 2009 Service and Repair.
4. Install positive crankcase ventilation cover on the cylinder head.
Positive crankcase ventilation cover 4-6
5. Fit hydraulic return line for power steering on the oil/water heat exchanger and secure it in the holder.
6. Completely install intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
7. Install the engine.
-> 100119 Removing and installing engine 100119 Removing and installing engine.