Part 1
Disassembling V8 4.8-liter DFI engine
Information
Component changes for model year 2009 as of October 2008
Information
Always read the information concerning modified tightening specifications and component changes relating to repairs provided for specific engine numbers in the Information section!
Preliminary work
1. Remove engine.
2. Remove engine from transmission.
3. Secure engine on assembly support.
4. Drain engine oil.
Disassembling V8 4.8-liter DFI engine
Disassembling V8 4.8-liter Turbo DFI engine
Caution
Emerging residual fluid can soil the engine!
Residual fluid (fuel, oil, Pentosin, coolant, etc.) will emerge even after a long time when disassembling and assembling the engine.
- Place a drip tray under the engine at the assembly support.
- Have a sufficient number of cleaning cloths ready.
- Close off engine openings with plugs.
Warning
The crankshaft is heavy!
There is a danger of hands being crushed when inserting the crankshaft.
- Hold the very outside of the crankshaft.
- Wear gloves.
Warning
Risk of damage to the engine and danger of crushing if the engine tips over
When removing and installing the vibration balancer with the engine removed (engine on assembly support), excessive use of force can cause the assembly mounting to become kinked.
- The engine must be supported at the oil pan or engine carrier using suitable lifting equipment and a wide wooden block. This applies to all engines and assembly mountings.
Caution
Interchanged or dirty bucket tappets.
Damage to engine components.
- The components have been run in in the fitting bores in the housing, therefore do not interchange them.
- Absolute cleanliness is essential.
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 DFI high-pressure pump, vacuum pump, injectors and exhaust manifold, 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.
2. Remove power-steering pump and air conditioning compressor if necessary.
3. Remove spark plugs.
4. Remove intake-air distributor.
5. Remove fuel distribution pipe.
6. Remove high-pressure pump at cylinder 8.
7. Remove vacuum pump -1- at cylinder 4. To do this, loosen the three screws -2-.
Vacuum pump
8. Remove tank vent and line -3-.
Oil mist separator for positive crankcase ventilation (M48/51 turbo engine)
9. Remove vent lines between the oil mist separator and timing-case cover and positive crankcase ventilation lines.
Positive crankcase ventilation, turbo engine M48/51
10. Remove high-pressure line from cylinder head -2-. To do this, remove the union nut -4-.
High-pressure pump on turbo engine M48/51, 6-piston pump
11. Remove vent line.
11.1. Unscrew fastening screws -1-.
11.2. Unclip vent line -2- from the cable duct and remove it -arrow-.
Removing vent line
12. Remove oil dipstick with guide tube -1-. To do this, loosen two screws -3 and 11- and pull out the guide tube.
Oil guide housing with accessories
13. Detach and remove the coolant hose assembly -2-. Remove coolant pipe -1-. Detach coolant hose from the generator -4 and 5-.
Coolant supply line on turbo engine M48/51
Coolant return line on turbo engine M48/51
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 lines for the wastegate and boost-pressure control. Mark lines and place aside in order.
Boost pressure and wastegate
Boost pressure and wastegate 2
16. Remove starter -1-. To do this, remove the screws -2-.
Starter
17. Remove engine wire harness and set it down safely.
Installation position of engine wire harness
Connector overview for engine wire harness
1-4 - Bar ignition module connectors for cylinders 1-4
5-8 - Bar ignition module connectors for cylinders 5-8
9-12 - Connectors for high-pressure fuel injectors (DFI) for cylinders 1-4
13-16 - Connectors for high-pressure fuel injectors (DFI) for cylinders 5-8
17-18 - Connectors for camshaft control hydraulic valves
19-20 - Connectors for solenoid/hydraulic valves for valve lift switchover
21-24 - Ground straps
25 - Crankshaft pulse sender on DFI engines
26-27 - Hall sender connectors (camshafts) on DFI engines
28-31 - Knock sensor connectors on DFI engines
32 - Tank vent connector
33 - Generator connector
34 - Crankcase heater connector
35 - Connector for flow control valve
36 - Connector for coolant temperature gauge
37 - A/C compressor connector
38 - Connector for oil pressure control valve
39 - Connector for oil level sensor
40 - Connector for oil pressure sensor
41 - Throttle valve connector
42 - Connector for high-pressure sensor
43 - Starter lead for terminal 50
44-45 - Starter lead for terminal 30
46 - Generator line for terminal 50
47 - B+ line for external power connection
48 - Connector for intake pipe switchover valve
49 - Clutch protection connector (only for vehicles with manual transmission)
50-51 - Plug connections between engine wire harness and main wire harness
52 - DME control unit connector
53 - Ground strap
18. Detach and expose vent lines for the turbocharger on the turbocharger and engine (cylinders 1 to 4 -1- and cylinders 5 to 8 -4-). To do this, loosen the union nut at the oil extraction line (counter!) and clamps. Remove vent lines from the engine. Loosen oil extraction lines at the oil guide housing (cylinders 1 to 4 -5- and cylinders 5 to 8 -8-). Loosen oil supply lines (cylinders 1 to 4 -2- and cylinders 5 to 8 -1-) at the cylinder head and crankcase (leave attached to the turbocharger).
Oil circuit for turbocharger, cylinders 1 to 4
Oil circuit for turbocharger, cylinders 5 to 8
19. Detach the turbocharger's coolant lines from the coolant hoses or coolant guide and from the clamps at the engine (leave attached to the turbocharger).
Turbocharger, cylinders 1 to 4 - cooling
Turbocharger, cylinders 5 to 8 - cooling
20. Remove turbocharger support between the turbocharger and the cylinder head.
Turbocharger, cylinders 1 to 4
Turbocharger, cylinders 5 to 8
21. Unscrew turbocharger from the exhaust manifold with the lines still attached and remove it. Then remove the exhaust manifold by loosening the nuts.
Exhaust manifold on turbo engine M48/51, cylinders 1 to 4
Exhaust manifold on turbo engine M48/51, cylinders 5 to 8
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
23. Remove water pump.
Coolant pump
24. Disconnect coolant pipe -1 at 9-. To do this, remove the screws -3-.
Coolant guide
25. Pull out intake socket for thermostat -6-. Detach thermostat housing and remove with the coolant pipe.
Thermostat housing
26. Remove coolant pipe on the right side -1-.
Coolant supply line on turbo engine M48/51
27. Disconnect PCV line on the engine. To do this, disconnect line at the turbocharger lines (clamp) and at the crankcase.
Positive crankcase ventilation (PCV), Turbo M48/51
28. 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