Disassembly
Disassembling and assembling engineTools
Preliminary work for disassembling engine
1. Remove engine.
2. Remove transmission.
Tiptronic transmission:
3. Remove converter housing.
4. Remove drive plate for converter.
Manual transmission:
5. Remove clutch.
6. Remove double-mass flywheel.
7. Remove rear silencer and catalytic converters.
Component overview - engine
Note: The overview graphics are shown schematically and may be different to how the components actually look.
Intake system, belt drive
^ 1 - Intake distributor
^ 2 - Belt drive
^ 3 - Belt guide and belt tensioner
Engine - lubrication
^ 4 - Oil pumps, heat exchanger, coolant guide housing
^ 5 - Oil pan, oil separator
Cylinder head, crankcase
^ 6 - Cylinder-head cover, camshafts, flat-base tappet housing, cylinder head
^ 7 - Cylinder head, flat-base tappets
^ 8 - Crankcase halves
Crank drive, pistons
^ 9 - Pistons, connecting rods
^ 10 -Bearing housing with intermediate shaft
^ 11 -Bearing housing halves with crankshaft
Disassembling engine - up to crankcase
ATTENTION: Risk of damage due to particles of dirt.
^ Oil bores/oil ducts can become blocked up.
^ When working on the engine, absolute cleanliness is essential.
^ Lay removed engine parts on a clean base and cover them without fail.
^ Use the cover for dust protection when fitting the engine NR.165 on the engine assembly support.
WARNING: Coolant is corrosive and hazardous to health.
^ Skin and eye irritation
^ Wear protective gloves and goggles.
^ If you come into contact with coolant, wash off immediately with plenty of warm water.
WARNING: Pentosin is hazardous to health
^ Danger of material damage and injury
^ Wear protective gloves and goggles.
^ If the eyes or skin come into contact with the fluid, 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.
Note: The bearing housing remains screwed to the retaining device when the bearing housing and intermediate shaft are disassembled.
1. Fasten the engine support 9589 to the crankcase using special tool mounting elements 9590. Refit engine with support on the engine assembly support.
2. Drain engine oil. Unscrew the oil drain plug (hexagon socket a/f 8).
3. Remove engine carrier. Unscrew M10 collar nuts and 1 M6 20 Torx screw.
4. Undo 3 M8 12 fastening screws on the belt pulley for the servo pump (do not remove).
5. Remove drive belt. Mark the running direction with a coloured 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.
6. Only for Tiptronic: remove guide for drive belt, to do this, unscrew two M6 20 Torx screws.
7. Unclip hose assembly on the intake distributor, cylinder side 1 -3:
8. Unplug crankcase ventilation line on pre-separator, cylinder 4-6.
9. Remove shields for ignition coils on the left and the right, unscrew 2 M6 16 fastening screws.
10. Disconnect electrical plug connections (engine wiring harness) on engine and unclip wiring harness on the fuel collection pipes.
^ 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 - 6 --
^ Two hall sender connectors
^ Plugs for speed sender
^ Plug for electrical switch-over valve (intake distributor 1-3)
^ Ground cable for front face of cylinder 4-6 (one M6 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 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 35 (micro-encapsulated) 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.
15. Only for 3.6l engine: Remove intake pipe support. Unscrew four M6 35 screws, unscrew one M6 12 screw for ground strap on cylinder bank - 6 - Take off intake pipe support, seal intake openings on cylinder head (e.g. with adhesive tape).
16. Only for 3.8l engine: Unscrew the four M6 35 Torx screws. Completely remove the intake distributor. Seal intake openings on cylinder head (e.g. with adhesive tape).
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.
19. Lift the generator out of the bracket and disconnect the two electrical connecting leads -Arrows-.
20. Remove mount for the coolant vent line. Unscrew one M6 16 (micro-encapsulated), remove mount, replace screw.
21. Unplug all vent lines for oil mist collector.
22. Unscrew the two M6 20 Torx screws on the oil mist collector mount and pull off collector. Replace two O-rings during installation. The screws tighten the secondary-air line on the cylinder head 4-6 at the same time.
23. Unscrew one fastening screw for the wiring harness guide on the bracket for the secondary-air pump -1- and unclip the guide -2- on the bracket -Arrow-.
24. Remove the secondary air pump. Unplug cable plug, unscrew three M6 20 Torx screws on the bracket -1- and completely take out the pump with bracket and line. Use new seals when installing.
25. Release the wiring harness on the holder before the heat exchanger. Then unscrew the plastic holder.
26. Undo the wiring harness on the centre 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 wiring harness.
27. Remove the oil filler neck. Unscrew 2 M6 16 Torx screws (micro-encapsulated), pull out oil filler neck, check the O-ring and replace if necessary.
28. Remove oil/water heat exchanger. Unscrew the four inner M6 16 Torx screws, take off heat exchanger. Replace O-rings during installation.
29. 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 30 at the front -Arrows-, one M8 12 at the back), take the servo pump with line and supply tank out of the bracket.
30. Remove bracket for servo pump. Unscrew M8 35 Torx screws, remove bracket.
31. Remove one M8 60 screw for deflection roller -1- and six M6 20 Torx screws for closure cap -2- with bleeder lines for coolant system.
32. Only in manual transmissions: Remove the starter. Unscrew two M10 35 Torx screws -1-, take off starter -2-.
33. 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 35 Torx screw each and take off the sensors.
34. Remove canister for additional volumes of crankcase venting to the cylinder heads 1-3 and 4-6. Unscrew two M6 25 Torx screws each, take off canister. Use new O-rings when installing.
35. Remove the holder for the main muffler on the left and right. Unscrew two M8 30 Torx screws each on the intake side and two M8 25 each on the exhaust side and take off mount.
36. Remove mount and sealing cap for hydraulic valves for camshaft adjustment -2-. Unscrew two M6 20 Torx screws each, take off mount and sealing cap.
37. Remove three ignition coils per cylinder side -1-. Unscrew 12 M6 25 Torx screws, pull off ignition coils.
38. Remove six spark plugs. Use only approved tool spark plug socket wrench 14 from Snap-On (in case ceramic body breaks).
39. 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.
40. Remove the exhaust manifold. Unscrew six M8 28 screws each, remove manifold and seal.
41. Remove coolant pipe for heating. Side 1-3: unscrew two M6 12 Torx screws, side 4-6: unscrew three M6 12 Torx screws, remove coolant pipe.
42. Remove oil pressure sensor on cylinder head cover -6 (a/f 19).
43. Remove the mount for the air conditioning compressor. Unscrew two M8 fastening screws, and remove bracket.
44. Remove hall sender. Unscrew 1 M6 16 pan-head screw (hexagon socket a/f 5, micro-encapsulated) and pull off hall sender, replace screws.
45. Remove knock sensors. Mark installation position (plug connection) with a paint marker, unscrew one M8 35 Torx screw each, pull sensors out of crankcase.
46. Remove speed sender, unscrew one M6 16 pan-head screw (hexagon socket a/f 5, micro-encapsulated), remove sender, replace screw.
47. 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 16 Torx screw (micro-encapsulated), replace screw.
48. Remove all plastic closure caps on the cylinder heads, and replace closure caps.
49. 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°.
Figure
50. Remove oil extraction pump cylinders 1-3 - Unscrew four M6 20Torx screws (micro-encapsulated), carefully pull the oil extraction pumps out of the fitting bore. Replace screws.
51. Remove tandem pump on cylinder side 4-6 - Unscrew four M6 30 fastening screws -1-, pull vacuum line -2- out of the connection fitting on the pump, take out the pump. Replace O-rings.
Removing camshafts, cylinder bank 1 - 3
Note: The central screws of the camshaft adjustment elements must be undone before removing the cylinder head cover.
52. 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.
Figure
53. Remove cylinder head cover.
54. Remove all chain tensioners, replace aluminium sealing rings.
55. Remove upper M6 screw (hexagon socket a/f 5) for guide rail cylinder 4-6.
56. Remove camshaft side 1-3.
ATTENTION: Interchanged or dirty flat-base tappets.
^ Damage to engine components
^ The components have been run in in the fitting bores in the housing, therefore do not interchange them.
^ Pay attention to cleanliness.
57. Remove the flat-based tappets. Pull the components out with a strong magnet out of the flat-base tappets housing. To avoid confusing the individual flat-based tappets, lay them on a labelled, clean surface (see example) and cover.
58. Unscrew the top M6 guide rail screw (hexagon socket a/f 5) on cylinder 4-6.
59. Remove camshaft side 4-6.
60. Remove flat-base tappet housing. Unscrew 11 M6 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.
61. Unscrew the top M6 guide rail screw (hexagon socket a/f 5) on cylinder 1-3.
62. Unscrew four M6 30 Torx screws -Pos 1 - - per cylinder bank.
63. Remove cylinder head. Undo and unscrew 12 M10 230 Torx screws from inside to outside on each cylinder head. Lift the cylinder header and seal off the crankcase.
64. Remove all carbon deposits and other residues on all six pistons with a brass brush, which will make the engraved markings -Arrow facing flywheel side- visible. Before removing, number and mark the pistons in the installation position.
65. Unscrew M27 aluminium screw plug for the assembly bore (piston pin).
66. Remove coolant closure cap (with connection for coolant ventilation). Unscrew six M6 20 inner Torx screws, remove cover, and replace the seal.
67. Remove connection supports for coolant hose on the top of the coolant guide housing. Unscrew two M6 20 Torx screws and remove cover.
68. Remove coolant temperature sensor (a/f 22).
69. Remove coolant closure cap at the bottom of the coolant guide housing. Unscrew four M6 20 Torx screws and remove cover.
70. Remove coolant pump. Unscrew seven hexagon-head bolts (two M6 30 and five M6 25) and remove pump.
71. Remove thermostat housing. Unscrew four M6 20 Torx screws and remove housing, including thermostat.
72. Remove coolant guide housing and oil pump. Unscrew ten Torx screws, from those, eight M6 20 and two M6 70, and carefully lift housing with seal (if needed, press lightly with a assembly lever). Pull out the driver for the oil pump. Remove the drive belt guide in Tiptronic vehicles.
73. Remove lower M6 guide and tensioning rail screws (hexagon socket a/f 5), remove the guide and tensioning rails from the chain spaces.
74. Remove oil filter with special tool release key 9204.
75. Unscrew 13 M6 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.
76. Remove air/oil separator (swirl pots) and oil suction pipe. To remove the separator, unscrew two M6 20 Torx screws and pull out the separator. Unscrew two M6 20 Torx screws on the oil suction pipe and remove the oil suction pipe.
77. Remove bearing cover for intermediate shaft.
78. Undo M16 1.5 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 - Screw on belt pulley-3.6l engine or holding wrench 9732. Do not unscrew the screw.