Part 1
WM 100137 Disassembling and assembling engine
Preliminary work for disassembling engine
Preliminary work for disassembling engine
1. Remove engine.
2. Remove transmission
3. Remove rear silencers and catalytic converters.
Tiptronic transmission:
Detach torque converter housing.
Removing drive plate for converter.
Manual transmission:
Remove clutch.
Remove dual-mass flywheel.
Component overview - engine
Component overview - engine
Information
The overview graphics are shown schematically and may be different to how the components actually look.
Intake system, belt drive
Peripheral engine component 1
1-Intake distributor
2-Belt drive
3-Belt guide and belt tensioner
Engine - lubrication
Engine - lubrication
4-Oil pumps, heat exchanger, coolant guide housing
5-Oil pan, oil separator
Cylinder head, crankcase
Cylinder head, crankcase
6-Cylinder-head cover, camshafts, flat-base tappet housing, cylinder head
7-Cylinder head, bucket tappets
8 Crankcase halves
Crank drive, pistons
Crank drive, pistons
9-Pistons, connecting rods
10-Bearing housing with intermediate shaft
11-Bearing housing halves with crankshaft
Disassembling engine down to crankcase
Disassembling engine down to crankcase
Caution
Risk of damage due to particles of dirt.
Danger of material damage due to blocked oil bores/oil ducts.
- Absolute cleanliness is essential when working on the engine.
- Lay removed engine parts on a clean base and make sure to cover them.
- Use the cover for dust protection when fitting the engine NR.165 on the engine assembly support.
Warning
Caustic fluid
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.
Warning
Pentosin is hazardous to health
Danger of material damage and injury
- Wear protective gloves and goggles.
- If the fluid gets into your eyes or on your skin, rinse or wash immediately with water.
- Collect emerging Pentosin. Clean hoses which come into contact with Pentosin thoroughly.
- Use caps to protect the wiring against soiling and damage.
Information
The bearing housing remains screwed to the retaining device when the bearing housing and intermediate shaft are disassembled.
1. Engine support 9589 must be secured to the crankcase using special tool mounting elements 9590. Refit engine with support on the engine assembly support.
Engine support
2. Drain engine oil. Unscrew the oil drain plug (hexagon socket a/f 8).
Oil drain plug
3. Remove engine carrier. Unscrew 4 M10 collar nuts and 1 M6 x 20 Torx screw.
Engine carrier
4. Undo 3 M8 x 12 fastening screws on the belt pulley for the servo pump (do not remove).
5. Remove drive belt. Mark the running direction with a colored pen, turn the tensioning roller (a/f 24) clockwise, hold still and simultaneously remove the belt from the drive pulleys. Check the belt for damage, replace if necessary.
Belt tensioner
6. Only for Tiptronic: remove guide for drive belt, to do this, unscrew two M6 x 20 Torx screws.
7. Unclip hose assembly on the intake distributor, cylinder side 1-3:
Vacuum lines
8. Unplug crankcase ventilation line on pre-separator, cylinder 4-6.
View of engine, side 4-6
9. Remove shields for ignition coils on the left and the right, unscrew 2 M6 x 16 fastening screws.
Ignition coil shield
10. Disconnect electric plug connections (engine wire harness) on engine and unclip wire harness on the fuel collection pipes.
View of engine, side 1-3
Three injection valve plugs per cylinder side -1-
Three ignition coil plugs per cylinder side -2-
Two plugs for camshaft adjustment hydraulic valves, two for valve lift adjustment hydraulic valves -3-
Plug for engine coolant temperature sensor, two plugs for oil pressure sensor on cylinder head cover 4 - 6 -4-
Two hall sender connectors
Plugs for speed sender
Plug for electric switch-over valve (intake distributor 1-3)
Ground cable for front face of cylinder 4-6 (one M6 x 12 Torx screw)
Plug for engine compartment temperature sensor (intake distributor 4-6)
11. Unclip fuel ring pipe on the engine eyelet and unscrew two M6 x 16 Torx screws, remove engine eyelet.
12. Detach holder for the throttle body on the servo pump. To do so, unscrew an M6 hexagon nut. Unplug cable plug for potentiometer and line for crankcase venting.
13. Undo holder for servo supply tank on intake distributor 4-6.
14. Only for 3.6l engine: Remove the relevant six M6 x 35 (micro-self-locking) fastening screws for the intake distributor on the intake pipe supports on the left and the right. Pull off one vacuum line and remove the intake distributor completely.
3.6l intake distributor
15. Only for 3.6l engine: Remove intake pipe support. Unscrew four M6 x 35 screws, unscrew one M6 x 12 screw for ground strap on cylinder bank 4-6. Take off intake pipe support, seal intake openings on cylinder head (e.g. with adhesive tape).
Intake pipe support
16. Only for 3.8l engine: Unscrew the four M6 x 35 Torx screws. Completely remove the intake distributor. Seal intake openings on cylinder head (e.g. with adhesive tape).
Intake distributor screw connection
17. Remove belt pulley from servo pump. Unscrew three fastening screws and remove belt pulley.
18. Remove generator. Undo the fastening screw on the deflection roller -1- and unscrew approx. three turns. Using an aluminium mandrel, tap lightly on the screw head to undo the pilot bushing in the generator swivel arm. Unscrew the screw and remove with the deflection roller. Unscrew the second screw -2- and carefully take out the generator.
Generator
19. Lift the generator out of the bracket and disconnect the two electric connecting lines -arrows-.
Electric connections on generator
20. Remove mount for the coolant vent line. Unscrew one M6 x 16 (micro-self-locking), remove mount, replace screw.
21. Unplug all vent lines for oil mist collector.
Oil mist collector - line connections for 3.8l engine
22. Unscrew the two M6 x 20 Torx screws on the 3.8l oil mist collector mount and pull off collector. Replace O-rings during installation. The screws tighten the secondary air line on cylinder head 4-6 at the same time.
Threaded joint for 3.8l oil mist collector
23. The oil mist collector on a 3.6l engine is removed in the same way as the 996 unit.
Oil mist collector on 3.6l engine
24. Unscrew one fastening screw for the wire harness guide on the bracket for the secondary air pump -1- and unclip the guide -2- on the bracket -arrow-.
Wire harness on secondary air pump
25. Remove the secondary air pump. Unplug cable plug, unscrew three M6 x 20 Torx screws on the bracket -1- and completely take out the pump with bracket and line. Use new seals when installing.
Secondary air pump with bracket
26. Release the wire harness on the holder before the heat exchanger. Then unscrew the plastic holder.
Wire harness on the heat exchanger
27. Undo the wire harness on the center of engine (connections to starter) -arrow- and unclip on the heat exchanger -1-. Unplug cable plug for knock sensors -2- and oil-level sensor. Then completely remove the engine wire harness.
Releasing wire harness
28. Remove the oil filler neck. Unscrew 2 M6 x 16 Torx screws (micro-self-locking), pull out oil filler neck, check the O-ring and replace if necessary.
Oil filler neck
29. Remove oil/water heat exchanger. Unscrew the four inner M6 x 16 Torx screws, take off heat exchanger. Replace O-rings during installation.
30. Remove hydraulic pump with servo line and supply tank. Undo servo line (a/f 16) -1-, counter on large hexagon when doing this (a/f 27). Unscrew four Torx screws (3 M8 x 30 at the front -arrows-, one M8 x 12 at the back), take the servo pump with line and supply tank out of the bracket.
Servo pump
31. Remove bracket for servo pump. Unscrew 4 M8 x 35 Torx screws, remove bracket.
Bracket for servo pump
32. Remove one M8 x 60 screw for deflection roller -1- and six M6 x 20 Torx screws for closure cap -2- with bleeder lines for coolant system.
Deflection roller and closure cap for coolant
33. Only in manual transmissions: Remove the starter. Unscrew two M10 x 35 Torx screws -1-, takeoff starter -2-.
Starter
34. Remove oil-level sensor (a/f 19), remove knock sensor, to do this, mark the installation position with a paint marker, then unscrew one M8 x 35 Torx screw each and take off the sensors.
35. Remove canister for additional volumes of crankcase venting to the cylinder heads 1-3 and 4-6. Unscrew two M6 x 25 Torx screws each, take off canister. Use new O-rings when installing.
36. Remove the holder for the main muffler on the left and right. Unscrew two M8 x 30 Torx screws each on the intake side and two M8 x 25 each on the exhaust side and take off mount.
NSD mount
37. Remove mount and sealing cap for hydraulic valves for camshaft adjustment -2-. Unscrew two M6 x 20 Torx screws each, take off mount and sealing cap.
Hydraulic valves for camshaft adjustment
38. Remove three ignition coils per cylinder side -1-. Unscrew 12 M6 x 25 Torx screws, pull off ignition coils.
39. Remove six spark plugs. Use only approved tool spark plug socket wrench 14 from Snap-On (in case ceramic body breaks).
40. Pull off hydraulic valves for camshaft and valve lift adjustment. To do this, the special tool relay puller 9235 can be used. Pull the oil strainer for the camshaft adjustment valve out of the valve bore -1- with a magnet, replace the oil strainer.
Oil strainer hydraulic valve NVS
41. Remove the exhaust manifold. Unscrew six M8 x 28 screws each, remove manifold and seal.
42. Remove coolant pipe for heating. Side 1-3: unscrew two M6 x 12 Torx screws, side 4-6: unscrew three M6 x 12 Torx screws, remove coolant pipe.
43. Remove oil pressure sensor on cylinder head cover 4-6 (a/f 19).
44. Remove the mount for the air conditioning compressor. Unscrew two M8 fastening screws, and remove bracket.
45. Remove hall sender. Unscrew 1 M6 x 16 pan-head screw (hexagon socket a/f 5, micro-self-locking) and pull off hall sender, replace screws.
46. Remove knock sensors. Mark installation position (plug connection) with a paint marker, unscrew one M8 x 35 Torx screw each, pull sensors out of crankcase.
47. Remove speed sender, unscrew one M6 x 16 pan-head screw (hexagon socket a/f 5, micro-self-locking), remove sender, replace screw.
48. Pull coolant hose assembly out of plastic holder on crankcase. Undo spring band clamps on water pump and thermostat and take off hoses. Remove mount, to do this, unscrew one M6 x 16 Torx screw (micro-self-locking), replace screw.
Mount for coolant hoses
49. Remove all plastic closure caps on the cylinder heads, and replace closure caps.
50. Turn engine on the belt pulley of the crankshaft clockwise to the overlapping TDC of cylinder bank 1-3. To check cylinder 1-3, insert the special tool adjusting gauge 9686 in the camshaft slots. If the gauge cannot be inserted, the engine must be turned an additional 360 degrees.
51. Remove oil extraction pump cylinders 1-3. Unscrew four M6 x 20Torx screws (micro-self-locking), carefully pull the oil extraction pumps out of the fitting bore. Replace screws.
52. Remove tandem pump on cylinder side 4-6. Unscrew four M6 x 30 fastening screws -1-, pull vacuum line -2- out of the connection fitting on the pump, take out the pump. Replace O-rings.
Tandem pump side 4-6
Information
The central screws of the camshaft control elements must be undone before removing the cylinder head cover.
This ensures that the camshafts are not under tension in the cylinder head and the valves are not touching against the pistons.
53. The central screws of the camshaft adjuster must be undone before removing the cylinder head covers. To do this, place special tool retaining tool 9685 on the large hexagon of the central screw and cylinder head cover and undo the screws.
Removing camshafts, cylinder bank 1-3:
54. Remove cylinder head cover 1-3.
55. Remove all chain tensioners and replace aluminium sealing rings during installation.
56. Remove upper M6 screw (hexagon socket a/f 5) for guide rail cylinder 4-6.
57. Remove camshaft side 1-3.
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.
58. Remove the bucket tappets. Pull each of the components out of the bucket tappet housing using a strong magnet. To avoid confusing the individual bucket tappets, lay them on a labelled, clean surface (see example) and cover them.
Example of laying aside bucket tappets
59. Place engine on the belt pulley of the crankshaft clockwise to the overlapping TDC of cylinder bank 4-6. To do this, turn the engine a further 360 degrees clockwise. To check cylinder 4-6, insert the special tool adjusting gauge 9686 in the camshaft slots.
Removing camshafts, cylinder bank 4-6:
60. Remove cylinder head cover 4-6.
61. Unscrew the top M6 guide rail screw (hexagon socket a/f 5) on cylinder 4-6.
62. Remove camshaft side 4-6.
63. Remove flat-base tappet housing. Unscrew 11 M6 x 35 Torx screws per housing, one 1/4-inch E10 socket is necessary for this. Take flat-base tappet housing out of the cylinder head. It is absolutely necessary to replace O-rings for spark-plug recesses when installing.
64. Unscrew the top M6 guide rail screw (hexagon socket a/f 5) on cylinder 1-3.
65. Unscrew four M6 x 30 Torx screws -Pos 1 - 4- per cylinder bank.
External cylinder head screwed connection
66. Remove cylinder head. Undo and unscrew 12 M10 x 230 Torx screws from inside to outside on each cylinder head. Lift the cylinder header and seal off the crankcase.
67. Remove all carbon deposits and other residues on all six pistons with a brass brush, which will make the engraved markings -arrow points to flywheel side- visible. Before removing, number and mark the pistons in the installation position.
Installation position of the pistons
68. Unscrew M27 aluminium screw plug for the assembly bore (piston pin).
69. Remove coolant closure cap (with connection for coolant ventilation). Unscrew six M6 x 20 inner Torx screws, remove cover, and replace the seal.
70. Remove connection supports for coolant hose on the top of the coolant guide housing. Unscrew two M6 x 20 Torx screws and remove cover.
71. Remove coolant temperature sensor (a/f 22).
72. Remove coolant closure cap at the bottom of the coolant guide housing. Unscrew four M6 x 20 Torx screws and remove cover.
73. Remove coolant pump. Unscrew seven hexagon-head bolts (two M6 x 30 and five M6 x 25) and remove pump.
74. Remove thermostat housing. Unscrew four M6 x 20 Torx screws and remove housing, including thermostat.
75. Remove coolant guide housing and oil pump. Unscrew ten Torx screws, namely eight M6 x 20 and two M6 x 70, and carefully lift off housing with seal (press lightly with an assembly lever if necessary). Pull out the driver for the oil pump. Remove the drive belt guide in Tiptronic vehicles.
Coolant guide housing screw connection
76. Remove lower M6 guide and tensioning rail screws (hexagon socket a/f 5), remove the guide and tensioning rails from the chain spaces.
77. Remove oil filter with special tool release key 9204.
78. Unscrew 13 M6 x 20 Torx screws on the oil pan cover. Tap cover gently on the sides using a plastic hammer, then carefully lift it at the leverage bar -see figure- using a plastic-coated mounting lever and remove the oil pan.
Lifting the oil pan cover
79. Remove air/oil separator (swirl pots) and oil suction pipe. To remove each separator, unscrew two M6 x 20 Torx screws and pull out the separator. Unscrew two M6 x 20 Torx screws on the oil suction pipe and remove the oil suction pipe.
Components in the oil pan
80. Remove bearing cover for intermediate shaft.
81. Undo M16 x 1.5 x 60 hexagon-head bolt for belt pulley or vibration damper with special tool socket wrench insert 9594, while countering with special tool retaining device 9593 or holding wrench 9732. Do not unscrew the screw.
Screw on belt pulley - 3.6l engine