Part 2

WM 101651 Partially Disassembling Engine - Sealing Joint (Continued)

58. Remove intermediate shaft housing.
59. Unscrew M16 x 1.5 x 60 hexagon-head bolt for pulley or vibration balancer with special tool socket-wrench insert 9594, while countering with special tool retaining device 9593. Do not unscrew the screw.





60. Unscrew inner Torx screw with O-ring M9 x 140 for bearing case -arrow- on crankcase half 4-6.





61. Turn crankcase at assembly support until crankcase half 4-6 stands vertically upwards.
62. Unscrew four coated M6 x 35 Torx screws -1- on crankcase half 4-6 on flywheel side. Replace screws during assembly.





63. Unscrew 20 remaining M6 x 35 Torx screws in the crankcase cross bolt connection.
64. Unscrew the star screw that fixes the crankcase half 4-6 to the engine support -arrow-.





65. Tap the crankcase halves gently with a plastic hammer. Carefully lever the various cast lugs with a screwdriver to separate the crankcase halves from one another.





Caution: Crankcase half 4-6 incorrectly levered off
^ Damage to pistons, piston rings

-> Lever off crankcase half 4-6 only with the help of a second person.

66. Carefully lever off crankcase half 4-6 with the help of a second person to avoid damaging the pistons (by tilting for example). Remove old shaft sealing rings.





Removing pistons, side 4-6:
67. Lever off the front piston-pin circlips of marked pistons 4-6 (from the viewpoint of the drive belt side) using a small screwdriver, push out the piston pin -arrow- and remove the pistons one by one. Assign the piston pins again to the appropriate pistons.


67.1. Replace piston-pin circlips during assembly.





68. Clean all the components.
68.1. Clean removed engine parts in a parts washing machine.

Sealing crankcase joint

Sealing crankcase joint

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.

Only the following sealants may be used to seal the engine:
^ Loctite 5900
^ Drei Bond 1209 (optional)

Note: Before placing the crankcase half 4-6 onto the connecting rods, slide on a protective tube or something similar to protect the cylinder lining from being damaged.

1. Prepare crankcase half 4-6 to fit it onto crankcase half 1-3. Carefully grease sealing faces of both halves with acetone. Align connecting rods 4-6 vertically upwards and fold timing chain.





2. Apply sealant to the sealing face of crankcase half 4-6 Application of sealant and tightening sequence for crankcase.





3. With the help of a second person, place crankcase half 4-6 in position on crankcase half 1-3. Knock gently on crankcase half 4-6 using a plastic hammer. Pull timing chain out through chain space using a bent welding wire.
4. Position four new, coated M6 x 35 Torx screws on flywheel side -1-.





5. Position seven M6 x 35 Torx screws on pulley side -1- ; then fit special tool centering mandrel 9645 for the intermediate shaft. Position centering mandrel on the mounting point of the oil pump and turn the star knob clockwise until it is braced in the crankcase.





6. Position the remaining 13 M6 x 35 Torx screws on the crankcase. Tighten all screws in the cross bolt connection to the required torque in accordance with the specified tightening sequence Application of sealant and tightening sequence for crankcase. -> Tightening torque: 13 Nm (9.5 ftlb.)
7. Carefully remove any remaining sealant on crankcase (particularly around the oil pan, intermediate-shaft bearing and crankshaft sealing rings).

Assembling engine

Assembling engine

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.

Note: All O-rings and seals (shaft seals), micro-encapsulated, coated screws or lock nuts must be replaced.

The engine is assembled in reverse order to disassembly. Components that are not replaced must be cleaned.

Markings on crankcase:

Engine number





Cylinder arrangement





1. Fit inner Torx screw with new M9 x 140 O-ring for bearing case -arrow- on crankcase half 4-6.
-> Tightening torque: 22 Nm (16 ftlb.)





2. Turn the crankcase at the assembly support so that cylinder bank 4-6 stands upwards.
3. Tighten third star screw for crankcase half 4-6 on engine support.





4. Fit crankshaft sealing ring on pulley side.
5. Only position pulley/vibration balancer with fastening screw (to turn the crankshaft).

Note: Used connecting rods do not remain upright when the pistons are assembled, and therefore the piston pins are fitted when the crankcase half 4-6 is positioned downwards.

6. Install pistons 4-6.
6.1. First turn connecting rod 6 to the BDC position and then remove the protective tube.
6.2. Press piston 6 into the cylinders just until the piston crown is flush with the crankcase sealing face.
6.3. Pay attention to direction of assembly: arrow on piston crown always points to flywheel side.
6.4. Turn the engine at the assembly support so that the crankcase 4-6 stands vertically downwards. Turn crankshaft slowly until connecting rod 6 is hanging vertically downwards in the TDC. Then fit piston pin and new circlip.
6.5. Turn engine again until crankcase half 4-6 is standing upwards. Fit pistons 5 and 4 in the same way as piston 6.





7. Once the pistons have been installed, seal the bore for the piston pin and circlip assembly on the crankcase using the aluminum screw plug and new sealing ring.
-> Tightening torque: 80 Nm (59 ftlb.)





8. Check the position of the crankshaft using the measuring mandrel 9699/1.





9. Fit crankshaft sealing ring on flywheel side. Use the insertion device 9699 for assembling.
10. Install intermediate shaft housing with a new sealing ring.
11. Install guide rail for cylinders 4-6. Insert guide rail with slot into the crankcase. Fit screw with new O-ring, grease the O-ring with Optimol MP3.
-> Tightening torque: 10 Nm (7.5 ftlb.)
12. Install tensioning rail for cylinder 4-6. Fit screw with new O-ring, grease the O-ring with Optimol MP3.
-> Tightening torque: 10 Nm (7.5 ftlb.)
13. Install oil pan. Apply a bead of sealant, Loctite 5900, to the cleaned and greased oil pan and secure with 13 M6 x 20 Torx screws from the inside out.
-> Tightening torque: 10 Nm (7.5 ftlb.)
14. Fit oil filter, grease new O-ring with Optimol MP3.
-> Tightening torque: 25 Nm (19 ftlb.)
15. Install oil pump with coolant guide. It is advisable to get a second person to assist to make assembly easier.
15.1. Remove centering mandrel for intermediate shaft.
15.2. Prepare oil pump with new seal and two new O-rings. Grease the O-rings with Optimol MP3.
15.3. Pull timing chain 4-6 outward so that the intermediate shaft is centered. Align driver for the oil pump and then push the housing together with the oil pump into the bearing seat.





16. Coat the thread of two M6 x 70 Torx screws -2- with Loctite 574 and position on oil pump housing. Position the remaining eight M6 x 20 Torx screws -3-.
Position one M10 x 60 Torx screw -1-.





16.1. Tighten all the screws.
-> Tightening torque: 10 Nm (7.5 ftlb.)
-> Tightening torque: 45 Nm (33 ftlb.)
16.2. On Tiptronic vehicles, also install belt routing -4-.
17. Fit pulley/vibration balancer.
18. Fix timing chains with chain sprockets, for example with the old O-rings from the oil suction pumps.





19. Fit new cylinder head gasket, the TOP marking is legible from above.
20. Fit cylinder head 4-6. Observe tightening sequence and tightening specification of cylinder-head screws (see table).








21. Tighten external M6 (Torx) cylinder-head screws.
-> Tightening torque: 13 Nm (9.5 ftlb.)





The threaded pin for guide rail 4-6 (pulley side) on the cylinder head is inserted only after the timing chain has been fitted on the camshaft wheels.
22. Insert three new O-rings in the spark-plug recesses, lightly coat with high-pressure grease. Fit bucket tappet housing with eleven M6 x 35 Torx screws and tighten screws from the inside out.
-> Tightening torque: 10 Nm (7.5 ftlb.)





Note: Re-insert flat-base tappets in the fitted bores in which they were positioned before the disassembly. The flat-base tappets have been run in the fitting bores in the housing and therefore may not be switched.

23. Coat bucket tappets with fresh engine oil and insert into the fitted bores in the bucket tappet housing (switching tappet with dowel pin on the inlet side).





24. Install camshafts and set timing.
25. Fit cylinder head cover. Eight new, coated screws -1- must be used for the threaded joints at the camshaft bearing locations. For each one, tighten 20 M6 fastening screws according to the tightening sequence. Of each of the sets of 20 screws, only position two screws on the oil suction pump side (or tandem pump) and only perform the final tightening after fitting the pumps.
-> Tightening torque: 13 Nm (9.5 ftlb.)





Sealant application on cylinder head cover





Tightening sequence for cylinder head cover





26. Install tandem pump and oil suction pump with new, micro-self-locking screws and new O-rings. Fit the line on the tandem pump with two new O-rings. Grease O-rings with Optimol MP3.
-> Tightening torque: 10 Nm (7.5 ftlb.)

Install engine accessories in the reverse order to that in which they were removed. Some additional instructions follow.

- Install six spark plugs: -> Tightening torque: 30 Nm (22 ftlb.); -> Tightening torque: 25 Nm (19 ftlb.)
- Six ignition coils: tighten two M6 Torx socket screws for each of them. -> Tightening torque: 10 Nm (7.5 ftlb.)
- Hall sender: use two new M6 micro-self-locking screws. -> Tightening torque: 10 Nm (7.5 ftlb.) ± 0.5 Nm (± 0.5 ftlb.)
- Exhaust manifold: use new M8 x 28 hexagon-head bolts. -> Tightening torque: 23 Nm (17 ftlb.)
- Fit oil separator with new O-rings. Screw in M6 x 20 fastening screws on support bracket (3.8-liter engine) or crankcase (3.6-liter engine). -> Tightening torque: 10 Nm (7.5 ftlb.).
- Install power-steering pump.
- Secure pulley for power-steering pump.
- 1. Hold pulley -2- with arm bracket Nr.193 -1-, tighten three screws -3-.
-> Tightening torque: 23 Nm (17 ftlb.)





- Intake manifold with intake pipe support on the 3.6 l: fit with four M6 x 35 Torx screws and new seals. -> Tightening torque: 10 Nm (7.5 ftlb.)
- Intake-air distributor in the 3.8 l: four M6 Torx screws. -> Tightening torque: 10 Nm (7.5 ftlb.)
- Install generator: tighten M8 hexagon nut for B+ cable to the specified torque. -> Tightening torque: 15 Nm (11 ftlb.)

Subsequent work

Assembling engine, touching up
1. Fit flywheel.
2. Fit clutch.
3. Fit converter housing.
4. Fit drive plate for converter.
5. Mount transmission.
6. Install engine.