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 engine from transmission. -> 100127 Removing engine from transmission and mounting engine on transmission 100127 Removing Engine From Transmission and Mounting Engine on Transmission
3. Secure engine on assembly support.
4. Drain engine oil. For details, see -> 170117 Changing engine oil and oil filter Removal and Replacement
Disassembling engine
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
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 spark plugs. -> 287020 Removing and fitting spark plugs Service and Repair
4. Remove tank vent line -3- and engine ventilation lines -1 and 2-.
Ventilation on naturally aspirated engines
5. Remove oil mist separator. -> 105519 Removing and installing oil mist separator Service and Repair
6. Remove intake-air distributor. -> 244619 Removing and installing intake-air distributor Service and Repair
7. Remove fuel distribution pipe. -> 243019 Removing and installing fuel distribution pipe Service and Repair
8. Remove high-pressure pump at cylinder 8. -> 246319 Removing and installing high-pressure pump 246319 Removing and installing high-pressure pump
9. Remove vacuum pump at cylinder 4. To do this, loosen the three screws. => Vacuum pump
Vacuum pump
10. Detach and remove the coolant hose assembly -5-. Remove coolant pipe -4-.
Coolant return on naturally aspirated engine
11. Remove water pump. -> 195019 Removing and installing coolant pump Service and Repair
Coolant pump
12. Remove vent line.
12.1. Unscrew fastening screws -1-.
12.2. Unclip vent line -2- from the cable duct and remove it -arrow-.
Removing vent line
13. Remove heat protection panels on both sides.
Heat protection panels on V8 naturally aspirated engine
14. Remove the generator. Expose the peripheral equipment and unscrew the generator.
14.1. Remove support bracket (crash support) -10- from the generator (two screws) -9-.
Auxiliary units
14.2. Remove fastening screws on the generator -2 and 3-.
Generator
14.3. Carefully remove generator and disconnect B+ cable. To do this, remove nut on the rear of the generator.
15. Remove high-pressure line -2- from the cylinder head. To do this, remove union nut -4-.
High-pressure pump on naturally aspirated engine
16. Disconnect the cable plug at the coolant regulator (thermostat insert) using pointed-nose pliers. Remove engine wire harness. For details, see -> 975219 Removing and installing wire harness for engine 975219 Removing and installing wire harness for engine
16.1. Unscrew fastening screws.
16.2. Lift engine wire harness up and out -arrow-
Loosening engine wire harness at the engine housing
17. Disconnect coolant pipe -1- at the collection pipe -6-. To do this, remove the screws -2-.
Coolant guide
18. Remove thermostat housing.
18.1. Pull out thermostat insert (coolant regulator) -5-. Pull out thermostat insert (coolant regulator) using a solid electric cable. For a detailed description of how to remove the thermostat insert, see -> 195819 Removing and installing coolant regulator 195819 Removing and installing coolant regulator (thermostat).
18.2. Detach thermostat housing and remove with the coolant pipe fitted.
Thermostat housing and coolant regulator
19. Remove metal pipe for coolant supply -2-. Remove coolant hoses and metal pipe -5 and 6-.
Coolant supply on naturally aspirated engine
20. Remove starter -1-. To do this, remove the screws -2-.
Starter
21. Remove exhaust manifold on both sides. To do this, expose cable for oxygen sensor (lambda sensor).
Exhaust manifold on naturally aspirated engine (cylinders 1 to 4 shown)
22. Remove engine carrier with engine mountings on both sides. Then remove the brackets for the auxiliary units. => Left bracket for auxiliary units and engine mounting => Right bracket for auxiliary units and engine mounting
Left bracket for auxiliary units and engine mounting
Right bracket for auxiliary units and engine mounting
23. 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
24. 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
25. 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
WARNING
Objects or loads falling down
- Risk of squashing or crushing
-> Secure components to prevent them from falling down.
Information
Support the engine at the oil pan or engine carrier using suitable lifting equipment and a wide wooden block.
26. 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
27. 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
28. Remove chain tensioner for timing chain from the timing-case cover. -5-
Chain tensioner
29. 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
