Part 1
WM 1001Z1 Disassembling engine
Tools
Preliminary work
1. Remove the engine. -> 100119 Removing and installing engine 100119 Removing and installing engine
2. Remove the transmission. -> 343527 Removing and mounting transmission
3. Secure engine on assembly support. -> 1001IN Securing engine on assembly support (mounting bracket) 1001IN Securing engine on assembly support (mounting bracket)
4. Drain engine oil. For details, see -> 170117 Draining and filling engine oil (changing engine oil) Removal and Replacement
Disassembling engine
CAUTION
Heavy components
- Risk of squashing
-> Wear personal protective gear.
-> Get someone to help if necessary.
WARNING
Objects or loads falling down
- Risk of squashing or crushing
-> Secure components to prevent them from falling down.
NOTICE
Interchanged or dirty bucket tappets
- Scoring on cylinder head
-> Since the bucket tappets have been run in in the fitting bores, do not interchange them.
-> Absolute cleanliness is essential.
Information
Have a collection pan and some cloths ready before starting work on the engine block. Close off open hoses immediately after opening them using suitable stoppers. Residual fluid can leak out.
Information
Support the engine at the oil pan or engine carrier using suitable lifting equipment and a wide wooden block.
Information
For many components, it is only necessary to partially disassemble the engine. The extent of disassembly depends on the damage and scope of repairs to be carried out.
When replacing the cylinder head gasket, many components, such as the vacuum pump, injectors and exhaust manifolds, remain on the cylinder head. In this case, the cylinder head can be lifted from the crankcase with all components intact.
1. Remove drive belt. -> 137819 Removing and installing drive belt Service and Repair
2. Remove power-steering pump and air conditioning compressor if necessary.
3. Remove front-axle final drive and the cross-shaft engine carrier. For a detailed description, see -> 398819 Removing and installing all-wheel final drive 398819 Removing and installing four-wheel final drive
3.1. First remove the cross-shaft engine carrier and cross shaft and carefully pull them out of the crankcase.
3.2. Remove front-axle final drive.
4. Remove spark plugs. -> 287020 Removing and fitting spark plugs Service and Repair
5. Remove tank vent line and engine ventilation lines. The engine ventilation system on turbo engines is designed with one-way plug connections. For details, see -> 1052IN Information on positive crankcase ventilation (full-throttle ventilation) - Turbo Service and Repair
Ventilation on turbo engines
6. Remove oil mist separator. -> 105519 Removing and installing oil mist separator Service and Repair
7. Remove intake-air distributor. -> 244619 Removing and installing intake-air distributor Service and Repair
8. Remove fuel distribution pipe. -> 243019 Removing and installing fuel distribution pipe Service and Repair
9. Remove high-pressure pump at cylinder 8. -> 246319 Removing and installing high-pressure pump Service and Repair
10. Remove vacuum pump at cylinder 4. To do this, loosen the three screws. => Vacuum pump
Vacuum pump
11. Remove low-pressure line -4- at the cylinder head.
High-pressure pump, turbo engine
12. Detach and remove the coolant hose assembly -5-. Remove coolant pipe -4-.
Coolant return on turbo engine
13. Remove water pump. -> 195019 Removing and installing coolant pump Service and Repair
Coolant pump
14. Remove vent line.
14.1. Unscrew fastening screws -1-.
14.2. Unclip vent line -2- from the cable duct and remove it -arrow-.
Removing vent line
15. Remove the generator. Expose the peripheral equipment and unscrew the generator.
15.1. Remove support bracket (crash support) -10- from the generator (two screws) -9-.
Auxiliary units
15.2. Remove fastening screws on the generator -2 and 3-.
Generator
15.3. Carefully remove generator and disconnect B+ cable. To do this, remove nut on the rear of the generator.
16. Remove lines for the wastegate and boost-pressure control => Boost pressure and wastegate => Boost pressure and wastegate 2. Mark lines and place aside in order.
Boost pressure and wastegate
Boost pressure and wastegate 2
17. Remove engine wire harness. Disconnect cable plug for the engine wire harness at the coolant regulator (thermostat insert) using pointed-nose pliers. For details, see -> 975219 Removing and installing wire harness for engine 975219 Removing and installing wire harness for engine
17.1. Unscrew fastening screws.
17.2. Lift engine wire harness up and out -arrow-
Loosening engine wire harness at the engine housing
18. Disconnect coolant pipe at the collection pipe. To do this, remove the screws -2-.
Coolant guide
19. Remove thermostat housing.
19.1. Pull out thermostat insert (coolant regulator) -5-. Pull out thermostat insert using a solid cable. For a detailed description of how to remove the thermostat insert, see -> 195819 Removing and installing coolant regulator Service and Repair.
19.2. Detach thermostat housing and remove with the coolant pipe fitted.
Thermostat housing and coolant regulator
20. Remove high-pressure line -2-. To do this, remove union nut -5-.
High-pressure pump, turbo engine
21. Remove starter -1-. To do this, remove the screws -2-.
Starter
22. Remove the two turbochargers with lines connected.
22.1. Disconnect lines at the engine (the lines remain fitted on the turbocharger).
Turbocharger, cylinders 1 to 4 - cooling
Turbocharger, cylinders 5 to 8 - cooling
Oil circuit for turbocharger, cylinders 1 to 4
Oil circuit for turbocharger, cylinders 5 to 8
Turbocharger exhaust manifold, cylinders 1 to 4
Turbocharger exhaust manifold, cylinders 5 to 8
23. Remove metal pipe for coolant supply -2-. Remove coolant hoses and metal pipe.
Coolant supply on turbo engine
24. Remove belt tensioner and deflection rollers. To do this, carefully lever off the covers on the rollers and unscrew the components. -1, 2, 3, 4-
Belt drive
25. Unscrew oil pressure sensor -3- with adapter -1- from the crankcase. To do this, remove the screws -4-.
Oil pressure sensor and oil pressure measuring point
26. Remove both cylinder head covers (valve covers). => Bar ignition modules and valve covers, cylinder row 1 to 4 => Bar ignition modules and valve covers, cylinder bank 5 to 8
Bar ignition modules and valve covers, cylinder row 1 to 4
Bar ignition modules and valve covers, cylinder bank 5 to 8
27. Loosen screw on vibration balancer by two turns -4 and 3-. To do this, hold a brace brace 9679/1 at the vibration balancer with the help of a second worker. Support the brace on the floor if necessary. A very high torque is required to loosen the screw (more than 800 Nm/592 ftlb.). A long 3/4-inch tool is the best tool to use for this. The engine should be supported to prevent it from tipping over.
Supporting engine (illustration shows V8 4.5-litre engine supported on assembly support)
Pulleys
28. Turn the crankshaft at the vibration balancer so that the staking bore of the vibration balancer is located approx. 45° degrees in front of the lower staking point on the timing-case cover. => Staking bore 45 degrees before TDC
Staking bore 45 degrees before TDC
29. Remove chain tensioner for timing chain from the timing-case cover. -5-
Chain tensioner
30. Loosen camshaft controller and sprockets on the four camshafts by 2 turns. Always counter at the hexagon on the components when doing this. => Sprocket => Camshaft controller
Sprocket
Camshaft controller
31. Remove vibration balancer.
32. Turn the engine around. The oil pan must be facing upwards.
33. Unscrew oil pan -1-. To do this, remove all the screws -5-. The seal must be replaced.
