Disassembly

WM 100137 Disassembling engine











Caution
When working on the engine, absolute cleanliness is essential! An engine cover should be used on the engine assembly support. Lay removed engine parts on a clean base and cover them without fail. Even the smallest particles of dirt can block up oil bores.

Caution
-> Pentosin is hazardous to the health!
-> 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!
-> Protect the leads against soiling and damage with caps!

Caution
Coolant is hazardous to the health and irritates the skin!
-> When handling coolant, wear protective gloves and goggles!
-> In case of contact with the skin or eyes, wash immediately with plenty of water!

Preliminary work

Remove transmission. In the case of Tiptronic transmissions the converter housing must also be removed.

Remove the clutch pressure plate including clutch drive plate. Unscrew 6 M8 x 16 pan-head screws crosswise in several stages. Remove the thrust plate, including the drive plate.





Remove the double-mass flywheel (DMF, manual transmission) or the drive plate for the torque converter (Tiptronic). Unscrew 8 M10 x 1 x 50 pan-head screws, remove DMF or drive plate. To counter, fasten toothed segment 9538/1 to the crankcase using an M12 x 50 hexagon-head bolt (fine thread).

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 hose assembly on the intake distributor, cylinder side 1 - 3: 2 hoses on the oil mist separator, 1 hose on the oil/water heat exchanger, 1 hose on the throttle body, 1 coolant ventilation hose.
4. Remove engine carrier. Unscrew 4 M10 collar nuts and 1 M6 x 20 hexagon-head bolt.





Intake distributor side 4 - 6

5. Remove the relevant 6 M6 x 35 (micro-encapsulated) fastening screws for the intake distributor on the intake pipe supports on the left and the right. Pull off 1 vacuum line and remove the intake distributor completely.
6. Undo 3 M8 x 12 hexagon-head bolts on the belt pulley for the servo pump (do not remove).
7. 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.





8. Remove belt pulley from servo pump. Remove the 3 hexagon-head bolts, remove the belt pulley.





9. Remove generator. Undo the hexagon-head bolt on the deflection roller -1- and unscrew by approx. 3 turns. Using an aluminum mandrel, tap lightly on the screw head to undo the front fastening bushing in the generator swivel arm. Unscrew the screw and remove with the deflection roller. Unscrew the second hexagon head bolt -2-.





10. Lift the generator out of the bracket and disconnect the 2 electrical connecting leads -arrows-.





11. Suction off as much Pentosin as possible in the upper supply tank for the power steering system.
12. Remove the supply tank. Turn bayonet lock in the direction indicated by the arrow and pull off the tank. Suction off as much Pentosin as possible in the lower supply tank. Dispose of the fluid in accordance with legal requirements.








13. Remove hydraulic pump and servo line. Undo the servo line to the pump (counter at the body) and remove it right arrow-. Then unscrew 4 hexagon-head bolts (3 M8 x 30 at the front -arrows-, 1 M8 x 16 at the back), take the servo pump out of the bracket.





14. Remove the holder for the main muffler on the left and right. Unscrew the relevant 4 M8 hexagon-head bolts and remove the holder.
15. Remove the exhaust manifold. Unscrew 6 M8 x 28 screws, remove manifold and seal.
16. Remove oil mist separator. Release 1 spring band clamp on the flange, unscrew 2 M6 x 16 pan-head screws (hexagon socket a/f 5). Remove oil mist separator, check O-ring and replace if necessary.
17. Remove shields for ignition coils on the left and the right, unscrew 2 M6 x 16 hexagon-head bolts.
18. Disconnect the electrical plug connections:

^ 6 x ignition coil plugs
^ 2 x camshaft adjustment hydraulic valves, 2 x valve lift adjustment hydraulic valves
^ 1 x coolant temperature sensor, 2 x oil pressure sensor on cylinder head cover 4 - 6
^ 2 x knock sensor, 1 x hall sender, side 1 - 3
^ 1 x OBD switch-over valve, 1 x oil-level sensor, 1 x oil pressure switch

19. Remove 6 ignition coils. Unscrew 12 M6 x 25 pan-head screws, pull off ignition coils.
20. Unscrew 6 spark plugs. Use only approved Snap-On tool (spark plug socket wrench) 14 (in case ceramic body breaks).
21. Pull out the oil dip stick and remove the guide tube. To do this, unscrew an M6 x 16 hexagon-head bolt, pull out the guide tube, check the O-ring and replace if necessary.
22. Remove the oil filler neck. Unscrew 2 M6 x 16 hexagon-head bolts (micro-encapsulated), pull out oil filler neck, check the O-ring and replace if necessary.
23. Remove secondary air lines Unscrew 4 hexagon-head bolts (side 1 - 3: 2 M6 x 20, side 4 - 6: 2 M6 x 16), remove the leads (replace seals during installation).
24. Remove holder for the coolant ventilation. Unscrew 1 M6 x 16 screw (micro-encapsulated), remove holder.
25. Remove bracket for servo pump. Unscrew 4 M8 x 35 hexagon-head bolts, remove bracket.
26. Remove deflection roller by unscrewing 1 M8 x 60 hexagon-head bolt, remove deflection roller.
27. Only in manual transmissions: Remove the starter. Unscrew 2 M10 x 35 (a/f 15) hexagon-head bolts, unscrew hexagon nuts on clamp 30 (M8) and clamp 50 (M6), remove the starter from the guide.





Intake pipe support side 4 - 6

28. Remove intake pipe support. Unscrew 4 M6 x 35 hexagon-head bolts -arrows-, unscrew 1 M6 x 12 screw for ground strap on cylinder bank 4 - 6, remove intake pipe support including the engine wiring harness.
29. Remove holder for air conditioning compressor and wire retainer.
30. Remove oil-level sensor (a/f 19) and oil pressure switch (a/f 24).
31. Remove oil pressure sensor on cylinder head cover 4 - 6 (a/f 19).
32. Remove hall sender. Unscrew 1 M6 x 16 pan-head screw (hexagon socket a/f 5) and pull off hall sender. Replace micro-encapsulated screws.
33. Remove knock sensors. Unscrew 1 M8 hexagon-head bolt (a/f 13), pull knock sensors out of crankcase.
34. Remove speed sender, unscrew 1 M6 pan-head screw (hexagon socket a/f 5), remove sender. Replace micro encapsulated screw.
35. Remove 3 coolant hoses. Undo 2 spring band clamps and 1 screw-type hose clamp and pull off hoses. Remove 1 holder by unscrewing 1 M6 x 12 hexagon-head bolt.
36. Remove oil extraction pumps. Unscrew 4 M6 x 20 hexagon-head bolts, carefully pull the oil extraction pumps out of the fitting bores.
37. Remove all plugs on the cylinder head.

Removing camshafts, cylinder bank 1 - 3

38. Turn engine on the belt pulley of the crankshaft to the overlapping TDC of cylinder bank 1 - 3.

Information
^ The central screws of the camshaft adjustment devices must be undone before removing the cylinder head cover.

39. Remove the cylinder head cover.
40. Pull off hydraulic valves for camshaft and valve lift adjustment. Lift the oil strainer for the camshaft adjustment valve out of the valve bore.

Caution
Do not confuse the flat-base tappets. The flat-base tappets have been run in the fitting bores in the housing. Therefore they must not be interchanged or soiled.





41. Remove camshafts and flat-base tappets. To avoid confusing the individual flat-base tappets, lay them on a prepared sheet of paper -see Figure- and cover them to prevent soiling.

Removal of camshafts, cylinder bank 4 - 6, is similar to the process for cylinder bank 1 - 3

42. Remove flat-base tappet housing. Unscrew 11 M6 x 35 pan-head screws (hexagon socket a/f 5), take the flat-base housing out of the cylinder head. The O-rings for the spark-plug recesses must be replaced during installation.
43. Unscrew the top M6 guide rail screw (hexagon socket a/f 5) on each cylinder bank.
44. Unscrew 4 M6 x 30 pan-head screws (hexagon socket a/f 5) on each cylinder bank -items 1 - 4-.





45. Remove cylinder heads. Undo and remove 10 M10 x 230 Torx screws from inside to outside on each cylinder bank. Lift the cylinder header and seal off the crankcase.





46. Number and mark the installation position of the pistons on the piston crown before removing them; in addition, make the engraved markings visible when cleaning -arrow faces flywheel side-.
47. Remove the primary chain tensioner for the intermediate shaft (oil filter area) (M27 hexagon socket a/f 32).





48. Remove intermediate shaft flange. Undo M8 lock nut using special tool (socket wrench) 9110 while holding it with a 7 x 1.1 screwdriver at the slotted thread pin. Unscrew 3 M6 x 20 hexagon-head bolts (micro-encapsulated) and the lock nut, remove flange.
49. Unscrew M27 aluminum screw plug for the assembly bore (piston pin).
50. Remove coolant pipe for heating. Side 1 - 3: unscrew two M6 x 12 hexagon-head bolts, side 4 - 6: unscrew three M6 x 12 hexagon-head bolts, remove coolant pipe.
51. Remove coolant closure cap (with connection for coolant ventilation). Unscrew 6 M6 x 20 hexagon-head bolts and remove cover.
52. Remove connection supports for coolant hose on the top of the coolant guide housing. Unscrew 2 M6 x 20 hexagon-head bolts and remove cover.
53. Remove coolant temperature sensor (a/f 22).
54. Remove coolant closure cap at the bottom of the coolant guide housing. Unscrew 4 M6 x 20 hexagon head bolts and remove cover.
55. Remove coolant pump. Unscrew 7 hexagon-head bolts: 5 M6 x 25 and 2 M6 x 30; remove pump.
56. Remove thermostat housing. Unscrew 4 M6 x 20 hexagon-head bolts and remove housing, including thermostat.





57. Remove coolant guide housing and oil pump. Unscrew 10 hexagon-head bolts: 8 M6 x 20 and 2 M6 x 70 and carefully pull off the housing. Pull out the driver for the oil pump. Remove the drive belt guide in Tiptronic vehicles.
58. Remove an M6 guide and tensioning rail screw (hexagon socket a/f 5), remove the guide and tensioning rail from the chain spaces.
59. Remove oil/water heat exchanger. Unscrew 4 M6 x 16 pan-head screws (hexagon socket a/f 5), remove heat exchanger. Replace O-rings during installation.
60. Turn crankcase by 180 degrees on the assembly support.
61. Remove oil filter with special tool (release key) 9204.
62. Unscrew 13 M6 x 20 hexagon-head bolts on the oil pan. Tap oil pan gently on the sides using a plastic hammer, then carefully lift it at the leverage bar -Figure- using a plastic-coated mounting lever and remove the oil pan.








63. Remove air/oil separator (swirl pots) and oil suction pipe. To remove the separator, unscrew 2 M6 x 20 hexagon-head bolts and pull out the separator. Unscrew 2 micro-encapsulated M6 x 20 hexagon-head bolts on the oil suction pipe and remove the oil suction pipe.





64. Undo hexagon-head bolt (M16 x 1.5 x 60) for the belt pulley using special tool (socket wrench insert) 9594 while countering it with special tool (retaining device) 9593 -see Figure-. Do not unscrew the screw.





65. Turn crankcase by 180 degrees on the assembly support. Unscrew M9 x 94 Torx screws for bearing housing -arrows- on cylinder bank 1 - 3.
66. Unscrew the M9 x 150 Torx screw for the bearing housing -arrow- on cylinder bank 4 - 6.





67. Turn crankcase by 90 degrees on the assembly support so that crankcase half 4 - 6 stands upwards. Unscrew 24 M6 x 35 hexagon-head bolts (2 micro-encapsulated) of the crankcase cross bolt connection.





68. Unscrew the star screw that fixes crankcase half 4 - 6 to the engine support -arrow-.





69. Tap the crankcase halves gently with a plastic hammer. Carefully lever the various cast lugs with a screw driver -see Figure- to separate the crankcase halves from one another.

Caution
-> Lever off crankcase half 4 - 6 with the help of a second person to avoid damaging the pistons.

70. Carefully lever off crankcase half 4 - 6 with the help of a second person to avoid damaging the pistons (e.g. by tilting). Remove old shaft seals.





Information
^ For safety reasons, the bearing housing must be fixed to crankcase 1 - 3 using at least 2 screws when removing the pistons.





71. For the following steps, fasten the bearing housing to crankcase housing half 1 - 3 with at least 2 cylinder head screws using spacer sleeves 9613 -see Figure-.

Tightening torque approx. 20 Nm (15 ftlb.)





72. Lever off the front piston pin circlips of pistons 4 - 6 (from the viewpoint of the belt pulley side) using a small screw driver, push out the piston pin -Figure- and remove the pistons one by one. Assign the piston pins again to the appropriate pistons.

Information
^ Join connecting rod and connecting rod bearing cover together again immediately after removal.
^ Con-rod bolts must be replaced.








Removing connecting rod using plastic mandrel (shop-made)

73. Remove pistons 1 - 3, including connecting rods. To do this, turn the crankshaft on the belt pulley until the respective connecting rod bearing cover stands upwards. Undo and remove the con-rod bolts (twelve-edged socket wrench insert a/f 14) -Figure-. Remove connecting rod bearing cover, carefully press connecting rod and pistons downwards out of crankcase half 1 - 3 using a shop-made plastic mandrel -see Figure below-.
74. Unscrew hexagon-head bolt of belt pulley and remove belt pulley.





75. Fix special tool (retaining device) 9607 to the bearing housing with 2 M10 x 25 hexagon-head bolts -arrows-.
76. Unscrew cylinder-head screws again with spacer sleeves 9613.

Information
^ The bearing housing remains screwed to the retaining device when the bearing housing and intermediate shaft are disassembled.

77. Screw in retaining eyes on retaining device 9607, lift bearing housing out of the crankcase half using a workshop crane or engine lifter.








Lifting bearing housing out of crankcase half 1 - 3

78. Disassemble bearing housing.
79. Remove crankcase half 1 - 3 from the engine holder.