Part 1
WM 100119 Removing and installing V8 4.8-litre DFI engine
Technical values
Preliminary work
Special equipment-specific features are described in the notes.
1. Raise the vehicle at the jacking points provided on a lifting platform. => Lifting the vehicle
2. Turn the steering wheel until the wheels are pointing straight-ahead. During repair work, the steering may be turned slightly to allow access to the clamping screw on the steering gear.
3. Put on protection covers.
4. Read out the DME fault memory. Write down or print the result. -> 0101IN00 Diagnostic system: reading out fault memory and activating systems Component Tests and General Diagnostics
5. Move Tiptronic selector lever to position N. Leave the ignition key inserted.
6. Remove front wheels. -> 44051900 Removing and installing wheel - section on "Removing" Removal and Replacement
7. Disconnect the battery. -> 9000IN00 Work instructions after disconnecting the battery
8. Remove front wheel housing liners. -> 505619 Removing and installing front wheel housing liner - section on "Removing" Service and Repair
9. Remove engine guard with transverse strut. -> 108019 Removing and installing engine guard (underbody panel) - section on "Removing" 108019 Removing and installing engine guard (underbody panelling)
10. Drain coolant. -> 193817 Draining and filling coolant on DFI engines (includes bleeding) - section on "Draining"
11. Remove engine compartment trim panels. -> 700219 Removing and installing front trim (engine compartment) - section on "Removing" 700219 Removing and installing front trim (engine compartment)
12. Move bonnet into service position. -> 553119 Removing and installing front pneumatic spring Service and RepairRemove the rubber engine compartment seal. -> 553319 Removing and installing front lid seal - section on "Removing" Service and Repair
13. Remove plenum panel cover. -> 664419 Removing and installing cowl panel cover - section on "Removing" Service and Repair
14. On vehicles with manual transmission, disconnect the connections between the manual transmission and vehicle.-> 343519 Removing and installing transmission - section on "Removing" .
15. Remove design cover for throttle valve. -> 108319 Removing and installing engine cover (design cover) on DFI engines - section on "Removing"
16. Evacuate the air conditioning system. -> 870317 Draining and filling refrigerant Service and Repair
Tools and materials
The following tools are described in Tools and Equipment, Section 3.0.13 "WE 1206" (exceptions are noted).
Lifting platform
Tool overview
Complete structure of the base carrier with mounting mandrels
Removing 4.8-litre DFI engine
WARNING
Highly inflammable or explosive materials
- Danger of fire or explosion
-> Avoid contact with hot parts or sources of ignition.
-> Use suction to remove ignitable vapours.
-> Attach warning sign in a clearly visible position.
WARNING
Caustic fluids
- Danger of chemical burns
-> Avoid contact with caustic fluid.
-> Wear personal protective gear.
-> Ensure that there is good ventilation.
-> If you do come into contact, wash off immediately with plenty of warm water and contact a doctor if necessary.
NOTICE
Aggressive fluids
- Risk of damage to components and surfaces
-> Do not spill fluids.
-> In the event of contact, wash the component or surface with water.
-> Replace components that are already damaged.
Information
- Because of the high loosening torques, the four fastening screws on the front-axle carrier and the two screws on the engine transverse bar can now be loosened. Loosen the screws by a maximum of one turn.
Special equipment-specific features are described in the notes.
1. Detach DME control unit with holder.
1.1. Unscrew fastening screws -1 -.
1.2. Unclip ground strap -2- on holder -arrow A-.
1.3. Slide the DME control unit and holder -3- to one side -arrow B- until the connectors are easily accessible.
Detaching DME control unit with holder
2. Release the latch for the engine wire harness connector -1 - ( -arrows A- ) and remove from the DME control unit -arrows B-.
Pulling off connector
3. Disconnect ground point -1-. Unclip rubber sleeve -3- from the plenum panel and expose the engine wire harness -2-.
Engine wire harness in plenum panel
4. Open the cover of the central electrical system on the left side of the vehicle. To do this, loosen four Torx screws -arrows-.
Torx screws for cover of central electrical system
5. Disconnect two connectors for the engine wire harness (white, red) -1 and 2- inside the central electrical system.
Detach the wire harness from the retaining clips inside the plenum panel, remove it and then expose it.
Cable plug for engine wire harness
6. For vehicles with PDCC, loosen the additional reservoir -1- on the plenum panel and lift it up.
PDCC reservoir
7. Disconnect B+ transfer point at the left of the engine compartment. => B+ transfer point
B+ transfer point
8. On V8 naturally aspirated engines, remove the intake pipe between the air cleaner housings. -> 243519 Removing and installing air box for throttle housing on DFI engines (intake pipes upstream of throttle valve) - section on "Removing"
9. Turbo engine:
Remove Y-shaped pipe ahead of the throttle valve. -> 243519 Removing and installing air box for throttle housing on DFI engines (intake pipes upstream of throttle valve) - section on "Removing"
10. Turbo engine:
Pull off both cable plugs for the mass air flow (MAF) sensors -1-. Disconnect the PCV line -2- on the right pressure pipe (PCV is positive crankcase ventilation).
PCV and MAF sensor
11. Turbo engine:
Disconnect the line -1- to the ambient air valves and expose it -2-.
Line to ambient air valves
12. Disconnect two oxygen sensor connectors at the left and right of the water splash panel and unclip the cables from the holders. Pull retaining clip straight off -arrow-.
Oxygen sensor connector
13. Detach two coolant lines -1 and 2- on the reservoir.
Coolant hoses
Loosen the torque support => Torque support. To do this, remove the screw on the engine and loosen the screw on the body. Then bend the torque support up.
Torque support
14. Disconnect the vacuum line at the vacuum pump connector on the engine -arrow-.
Vacuum line to vacuum pump
15. Empty the power-steering fluid reservoir -1- (and PDCC reservoir) with a syringe. Then detach hose -2 and 3- from the reservoir. Close off open connections with stoppers.
Reservoir
16. Disconnect fuel line -4- and line from the carbon canister -2- on the plenum panel splash panel. Disconnect vacuum line -3-. Unclip engine wire harness -1- and place it on the engine.
Lines on plenum panel
17. Loosen three fastening screws for the spring struts at the left and right.
Spring strut screws
17.1. Loosen the screws from the engine compartment. Of the three screws per spring strut, one is in the plenum panel -1-.
17.2. Replace screws.
18. Disconnect the coolant supply and return lines from the radiator.
To do this, pull out the securing clip and pull off the connection. The clips should be fitted again immediately to ensure that the correct clip is used at the correct position.
On V8 turbo engines, the right pressure pipe -1- must be removed in order to reach the connection piece.
Securing clip on connection for coolant pipe
Boost pressure pipe
19. Lift up the top coolant pipe -1- and clamp it at the engine.
Remove both suction pipes -2- (turbo engine) from the air cleaner housings and bend them to the engine. Secure in place with two rubber straps if necessary. -arrows-
Pipes
Information
- In the case of vehicles with air suspension, the compressed air line on the spring strut must also be disconnected. Loosen the line carefully and allow the remaining pressure to escape. Loosen the threaded joint completely only when the line is fully depressurised.
Compressed air line on spring strut
- The electric plug connection of the height sensor must be disconnected in vehicles with air suspension or automatic headlight levelling system.
Electric plug connection for height sensor
20. Raise the vehicle halfway.
21. Disconnect electric connector for the wear indicator -1-.
21.1. Unclip holders -2 and 3- and expose the cable.
Cable guide at spring strut 2
22. Disconnect and expose cable for the ABS sensor => Cable guide at spring strut 1.
22.1. Unplug sensor on the air spring strut.
Cable guide at spring strut 1
23. Disconnect brake lines -arrow-.
Brake lines in wheel housings
24. Vehicles with air suspension:
24.1. Remove air suspension hose -arrow-.
Compressed air line
24.2. Unplug cable plug -arrow- on sensor for headlight levelling system.
Sensor for headlight levelling system
25. Turbo engine:
Remove both pressure pipes.
Left pressure pipe
25.1. Release the wire clips on the connection piece -1-.
25.2. Pull off pipe and fit wire clips again.
25.3. Release spring band clamp and remove pressure pipe.
26. Disconnect the ground point -arrow- on the right side member.
Disconnecting ground cable
27. Disconnect ATF lines on the radiator.
27.1. Loosen the fastening screw -arrow- and pull off the lines.
27.2. Close off open lines with stoppers. => Disconnecting ATF lines
Disconnecting ATF lines
28. Remove heat shield on the steering gear. To do this, loosen two fastening screws -arrows-.
Heat shield on steering gear
29. Release universal joint on the steering gear -arrow- and pull it out. The screw must not be re-used.
Clamping screw on steering column
Information
- In the case of vehicles with Servotronic, an electric plug must also be removed from the steering gear.
30. Disconnect electric connector -arrow- on the steering gear (Servotronic only). Figure shows right-hand drive vehicle.
Servotronic cable plug
31. Disconnect the heat exchanger coolant lines at the bottom of the left wheel housing -arrows-. Approx. 2 litres of coolant will flow out when you do this.
Heat exchanger coolant lines in left wheel housing
32. Remove the complete exhaust system from the connection point behind the catalytic converters as far as the tailpipes. -> 260119 Removing and installing exhaust system on DFI engines - section on "Removing" Testing and Inspection
33. Loosen the catalytic converter holders on the body -1-. The screws on the cross member -2- remain fitted.
Fastening screws on body and cross member
34. Remove rear cardan shaft. -> 393519 Removing and installing rear cardan shaft 393519 Removing and installing rear cardan shaft
35. Release heat shield above the right electric connections -1, 2 and 3- and disconnect them on the transmission.
Unclip the wire harness.
Electric connections on transmission
36. Loosen electric connections on the transfer gear -arrow-.
Connections on transfer gear
37. Detach the selector lever cable on the transmission. Do not loosen nut -2-.
37.1. Press the ball socket -arrow- away from the transmission.
37.2. Then pull out the top sheetmetal clip -1- and remove the cable in an upward direction.
Selector lever cable on transmission
38. Disconnect the lower line on the power-steering fluid cooler -arrow-. Close off connections.
Lower line on power-steering fluid cooler
39. Turbo engine:
Remove the hose -3- between the ambient air valve and intake pipe -1- on both sides by loosening the hose clamp -2-.
Connection between ambient air valve hose and intake pipe
40. Disconnect connections for the PDCC lines around the front axle and close off the connections.
40.1. Use two open-ended wrenches to open the two lines on the front right side member -arrows- (counter at the hexagon).
Front right PDCC lines
40.2. Detach and expose lines -arrows- from the valve block in the right wheel housing (close off connections).
PDCC line in right wheel housing
40.3. Detach line on distributor under the transfer gear and close it off. => PDCC line on distributor under front-axle final drive Expose line.
PDCC line on distributor under front-axle final drive
40.4. Disconnect PDCC line on the front axle using two open-ended wrenches and expose the line. => PDCC line on front axle
PDCC line on front axle
41. Unscrew fastening screws for refrigerant lines -1- and pull off refrigerant lines -2 and 3- ( -arrow- ).
Disconnecting refrigerant lines on air-conditioning compressor