Overhaul

WM 157019 Removing and installing cylinder head on V6 DFI engines

Technical values





Preliminary work

1. Remove belt tensioner. => 137319 Removing and installing belt tensioner on DFI engines - section on "Removing"





Belt tensioner





2. Release the engine wire harness around the cylinder head. => 97522100 Removing wire harness for engine (V6)
3. Remove bar ignition modules. => 282020 Removing and installing DFI bar ignition modules
4. Remove intake-air distributor. => 244619 Removing and installing DFI intake-air distributor - section on "Removing"
5. Remove cylinder head cover (valve cover).=> 158219 Removing and installing cylinder head cover on V6 DFI engines
6. Remove upper timing-case cover. => 153319 Removing and installing timing-case cover on V6 DFI engines - section on "Removing"
7. Set cylinder 1 to compression TDC. => 150502 Checking the timing on V6 DFI engines
8. Remove timing chain from the camshaft controllers and set it aside. To do this, remove both camshaft controllers. => 158419 Removing and installing camshaft controller on V6 DFI engines

Removing cylinder head

CAUTION

Heavy components

- Risk of squashing

-> Wear personal protective gear.
-> Get someone to help if necessary.

1. Remove screws used to secure the timing case to the cylinder head. -1-





Lower timing-case cover

Information

- If more extensive work was carried out, e.g. if the cylinder head was replaced, the exhaust manifolds, fuel injectors, fuel distributor pipe, combination valve, timing chain housing and various small parts must also be modified. Refer to => 1001AW The most important working regulations and warning notes.

2. Remove cylinder head. Loosen the screws one after the other in the opposite sequence to the sequence shown, i.e. start at cylinder-head screw 20 and loosen cylinder-head screw 1 last.





Cylinder head






Installing cylinder head

Information

If cold or excessively low-tempered components are sealed to each other by applying sealant, leaks can occur because of condensed water forming or components distorting. Components must be uniformly at least => Temperature: 17°C.

1. Install cylinder head.





Cylinder head





Information

- It is best to use only a spatula and acetone to clean the sealing faces. Ensure good ventilation because of the acetone.

- Use a cleaning cloth to wipe the sealing faces clean and remove any grease.

- Replace the cylinder-head gasket.

- Replace the cylinder-head screws with new ones.

1.1. Thoroughly clean all sealing faces before assembly.
1.2. Cylinder head gasket must always be replaced.
1.3. Always observe tightening sequence (1-20) for cylinder-head screws -1 to 20- and tighten to the specified torque.
1.3.1. Tighten cylinder-head screws to an initial tightening torque of 15 Nm (11 ftlb.).
1.3.2. Tighten cylinder-head screws to 30 Nm (22 ftlb.).
1.3.3. Then tighten all cylinder-head screws a second time to 30 Nm (22 ftlb.).
1.3.4. And finally, tighten the cylinder-head screws to a torque angle of 180°.
2. Secure the timing case to the cylinder head. -1- Fit both M8 screws => Tightening torque: 23 Nm (17 ftlb.).





Lower timing-case cover

Subsequent work

1. Fit both camshaft controllers. => 158419 Removing and installing camshaft controller on V6 DFI engines
2. Fit the timing chain on the camshaft controllers. => 153519 Removing and installing timing chains on V6 DFI engines





Component overview of timing chains





2.1. Install chain tensioner. => 153619 Removing and installing chain tensioner on V6 DFI engines

NOTICE

Incorrect handling of crankshafts

- Risk of damage to the timing system

-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.

3. Check the timing. => 150502 Checking the timing on V6 DFI engines
4. Fit upper timing-case cover. => 153319 Removing and installing timing-case cover on V6 DFI engines
5. Install cylinder head cover. => 158219 Removing and installing cylinder head cover on V6 DFI engines
6. Install belt tensioner. => 137319 Removing and installing belt tensioner on DFI engines
7. Fit and tension the drive belt.
=> 137819 Removing and installing drive belt





Fitting sequence





8. Install intake-air distributor. => 244619 Removing and installing DFI intake-air distributor - section on "Installing"
9. Install bar ignition modules. => 282020 Removing and installing DFI bar ignition modules
10. Install engine wire harness. => 97522100 Removing wire harness for engine (V6)