Disassembling and Assembling Engine

WM 100137 Disassembling and assembling engine

Tools and materials

Required special tools

Information:
The special tools that are required are described in the chapter, refer to: (Special) tools required for repairing the M48/00 and M48/50 engines or in the corresponding individual chapters.

Technical values

Technical values

Information:
For information on all tightening torques, refer to: Tightening torques for Cayenne S (M48/00) and Cayenne Turbo (M48/50) or the corresponding individual chapters.

Preliminary work

Preliminary work for disassembling engine

1. Remove engine.
2. Remove engine from transmission.

Information:
The engine must be disassembled in accordance with the detailed descriptions in the Technical Manual!
This chapter does not provide details or further information. Further details can be found in the relevant individual descriptions.

3. Secure engine support P 9676 on engine. To do this, use the four screws for mounting elements 9590 and tighten them slightly. Secure engine on engine support. To do this, carefully guide the engine support axle into the take-up bore on the engine support and secure it.

Crankcase on engine support (shown with lower part of crankcase)

4. Remove wire harness for engine.
5. Remove the generator.
6. Remove power-steering pump.
7. Remove left additional assembly bracket -2- and right engine carrier -8-. There are also two dowel sleeves (not shown) on the additional assembly bracket.

Removing and installing engine support

1 - Nut - Tightening torque: 75 Nm (56 ftlb.)
2 - Additional assembly bracket, left
3 - Screw x 10 - Tightening torque: 65 Nm (48 ftlb.)
4 - Hydraulic mount, left
5 - Engine carrier
6 - Screw x 4 - Tightening torque: 60 Nm (44 ftlb.)
7 - Hydraulic mount, right
8 - Engine carrier
9 - Screw x 6 - Tightening torque: 65 Nm (48 ftlb.)

Disassembling engine

Information on removing and installing the vibration balancer on the removed unit

Warning:
Risk of damage to the engine and danger of crushing if the engine tips over
When removing and installing the vibration balancer with the engine removed (engine on assembly support), excessive use of force can cause the assembly mounting to become kinked.

- The engine must be supported at the oil pan or engine carrier using suitable lifting equipment and a wide wooden block. This applies to all engines and assembly mountings.

Supporting engine (illustration shows V8 engine supported on the assembly support)

Disassembling engine

1. Remove starter.
2. Remove knock sensors.
3. Remove cylinder heads.
4. Remove water pump.
5. Remove coolant regulator.
6. Remove guide and tensioning rails.
7. Remove crankshaft.
8. Remove oil spray jets on turbo engine and cap on naturally aspirated engine.

Preliminary work

Preliminary work for engine assembly

1. The crankcase must be prepared for installation (dowel sleeves, caps and pins screwed in).

Information:
The engine must be disassembled in accordance with the detailed descriptions in the Technical Manual!
This chapter does not provide details or further information. Further details can be found in the relevant individual descriptions.

2. Attach top section of crankcase to engine support. To do this, use the four screws for mounting elements 9590 and tighten them slightly.

Crankcase on engine support

Assembling engine

Assembling engine

Caution: Leaks due to components being at too low a temperature or at different temperatures!
If components that are cold or at different temperatures are sealed together by the application of sealant, adhesion problems and leaks can arise due to the build-up of condensation water or component distortion.

- Components must have reached at least 17°C throughout.

- Components must not be too hot (distortion).

- Spare parts that are stored in the cold or heat (strong sunlight), must be brought to room temperature or the same temperature as other parts before installation.

Information:
The engine must be disassembled in accordance with the detailed descriptions in the Technical Manual!
This chapter does not provide details or further information. Further details can be found in the relevant individual descriptions.

Information:
Four oil spray nozzle are installed in the M48/50 engine instead of the caps used in the M48/00 engine.

1. Fit caps on crankcase. When doing so, make sure that new O-rings are fitted. Tighten the - Tightening torque: 10 Nm (7.5 ftlb.).

Caps and oil spray nozzles

Information:
The bearing shells are available in various tolerance classes. The classes are indicated by the color marking on the outside. The color marking must match the corresponding color dot on the crankshaft.

Color marking on bearing shell

2. Insert the bearing shells with the lubricating groove into the upper part of the crankcase. Make sure the twist locks are positioned correctly. Then lightly oil the bearing locations.

Inserting bearing shells

3. Insert the sickle-shaped washers (make sure of axial bearing play). To do this, insert the two sickle-shaped washers to the left and right on crankshaft bearing no. 3. Apply some grease (000.043.204.17) between the crankshaft bearing and the sickle washers so that the sickle washers do not fall down. Each of the lubricating grooves of the sickle-shaped washers must face outwards.

Inserting sickle-shaped washers

Warning:
The crankshaft is heavy!
There is a danger of hands being crushed when inserting the crankshaft.

- Hold the very outside of the crankshaft.

- Wear gloves.

4. Insert crankshaft. The connecting flange must point towards the back of the engine. Then secure the crankshaft from falling down using holding bridges 9677. Attach the holding bridges at bearing locations 3 and 5. Then screw the fastening screw of the front pulley into the crankshaft until they just make contact.

Crankshaft holding bridges

5. Turn crankcase by 180° on the assembly support.

Information:
The pistons must already be pre-fitted (pistons, piston rings, connecting rods and fastening material) before performing the next step.
The required bearing shells must be inserted in the connecting rods.
The connecting rod is symmetrical and can be fitted either on the piston so that the number on the connecting rod is facing outwards or inwards, or the tolerance class designation of the piston does not have to be on the same side as the connecting rod code. The direction of travel arrow is on the same side as the connecting rod code -A- as is evident on the piston shown. This can be installed as standard on one cylinder bank side on the same side as shown here, and on the other cylinder bank side, the connecting rod code is on the opposite side. The connecting rod code is installed to the exhaust side as standard.
When installing the piston in the crankcase, the direction of travel arrow must point in the direction of travel.

Connecting rod code and direction of travel arrow

The code on the connecting-rod big end and connecting-rod bearing cap must be on the same side and at the exhaust side.

Connecting rod code "A"

6. Install piston. To do this, turn the crankshaft with a wrench (a/f 27) until the corresponding lift pin is pointing straight downwards.

Turning the crankshaft

7. Lightly oil cylinder and piston.
8. Align piston-ring set (offset by 120°) and compress piston rings using piston ring restraining strap for 944 - S2 and Boxster and 911 Carrera (996) 57.

Tensioning the piston rings

9. Place piston onto cylinder from above and push into cylinder. When doing so, make sure that the direction of travel arrow is pointing forwards (in direction of travel). -Arrow-

Direction of travel arrow

Push piston in using the handle of a hammer, if necessary.

Sliding in the piston

10. Push the piston downwards until the connecting-rod bearing is sitting on the lift pin. Then fit connecting-rod bearing cap with bearing shell. The connecting rod numbers must face each other. Screw in con-rod bolts by hand. Make sure the twist locks and connecting rod code are positioned correctly during assembly.

Twist lock on bearing shells

View of connecting rod numbers

11. Fit the opposite piston (e.g. 1 and 4).
12. Fit other pistons in accordance with the step above.
13. Turn crankcase on the assembly support until the crankshaft is on top.

Information:
Con-rod bolts must always be replaced.

14. Tighten con-rod bolts that have been replaced.
15. Holding bridges 9677 must be removed from the crankshaft.
16. Screw the two thin centering pins 9321 into the outer fastening bores on the upper part of the crankcase -Arrows- (crankshaft not fitted in illustration).

Centering pin

17. Insert the bottom bearing shells into the lower part of the crankcase (bed plate) and lightly oil running surfaces. Pay attention to the twist locks when doing so.

Inserting the bearing shells

18. Make sure the crankcase is ready to be screwed in. Check that the sickle-shaped washers are positioned correctly. Degrease parting surfaces between upper and lower parts of the crankcase. A totally grease-free product (e.g. brake cleaner) must be used for this. Then insert a new O-ring at the front of the parting surface.

Lower part of crankcase (bed plate)

1 - Crankcase, lower part
2 - Cylindrical pin used to center the lower part of the crankcase on the crankcase
3 - Sealing ring; replace
4 - Application of sealant; liquid sealant 000.043.204.58 (status 02/06) must be applied and the screws screwed in within five minutes and without interruption
5 - Thrust-bearing screw, M12 x 1.5 x 132
6 - Thrust-bearing screw, M10 x 117
7 - Fastening screw, M8 x 70
8 - Fastening screw, M8 x 35
9 - Fastening screw, M8 x 50
10 - Dowel sleeve

Information:
Liquid sealant must be applied and screws tightened immediately and without interruption.
The threads and head contact surface of the bearing seat screws (M10 x 1.5 and M12 x 1.5) must be oiled.

19. Apply liquid sealant 000.043.204.58 (status 02/06, for details of current sealant, see Parts Catalogue) to the lower part of the crankcase as shown. The surfaces marked -A- must be cleaned after fitting.

Applying sealant to lower part of crankcase

20. Place lower part of crankcase into position. When doing so, make sure that the sealing bead is not destroyed.
21. For details of the tightening sequence for the lower part of the crankcase and tightening torques, refer to: Removing and Installing Crankshaft.
22. Then tighten the four fastening screws on the clutch side - Tightening torque: 23 Nm (17 ftlb.) -Arrows-.

Lower part of crankcase (clutch side)

23. Fit chain drive sprocket on the crankshaft. Unscrew fastening screw on belt pulley. Check that the feather keys are fitted correctly and push on the chain sprocket with the oil pump drive chain. The double-tooth row must be facing forwards.

Chain drive sprocket

24. Install oil pump.

Oil pump

25. Fit guide rail -9- and tensioning rail -6- for the oil pump drive. Push the tensioning rail over the fastening pin and engage the guide rail in the lower part of the crankcase as shown in the illustration.

Oil pump components

26. Fit timing chain cover on oil pump. Tighten - Tightening torque: 10 Nm (7.5 ftlb.).

Timing chain cover on oil pump

27. Turn engine 180° on the assembly support.
28. Install starter.

Installing starter

29. Fit knock sensors. Align the knock sensors as shown in the illustration and tighten the - Tightening torque: 23 Nm (17 ftlb.).

Figure shows knock sensor on bank 1 - 4

Figure shows knock sensor on bank 5 - 8

30. Install thermostat housing. Fit a new O-ring at the water pump inlet and then insert the thermostat housing. Tighten the two - Tightening torque: 10 Nm (7.5 ftlb.).
31. Mount cylinder heads. To do this, turn the engine on the assembly support so that the required cylinder row is pointing vertically upwards.
32. Fit new cylinder-head gasket. The gasket designation is shown on the back and is legible from above when fitted correctly.

Cylinder row 1 - 4

Cylinder row 5 - 8

33. Fit cylinder head. The fastening screws must be tightened in the sequence shown below. The tightening sequences and step-by-step tightening torques must be observed!

Tightening sequence for cylinder head

34. Fit camshaft housing. Apply a bead of liquid sealant 000.043.204.58 (status 02/06, for details of current sealant, see Parts Catalogue) -A- as shown. Then screw two thin centering pins 9321 into two opposing blind holes in the cylinder head. Insert the O-ring -B- into the oil duct. Wipe off any sealant -C- that emerges as a result of screwing.

Applying sealant

35. Position camshaft housing and then unscrew the two centering pins.
36. Tighten the camshaft housing screws in the sequence shown. Don't forget the two hexagon socket head bolts at the front of the camshaft housing.

Tightening sequence for camshaft housing

Screws at the front

Information:
The bearing locations of the camshafts must be lightly oiled.
Place the camshafts in such a way that the cams are positioned as shown below!

37. Install camshafts.

Positioning camshafts

1 - Cam position cylinder 6
2 - Cam position cylinder 2 (A) and cylinder 3 (B)
D - Cam position cylinder row 5 - 8 exhaust side
C - Cam position cylinder row 5 - 8 inlet side
B - Cam position cylinder row 1 - 4 inlet side
A - Cam position cylinder row 1 - 4 exhaust side

38. Fit oil return line to camshaft housing 5 - 8. Fit oil return line -1- with a new O-ring -2-. Tighten the four - Tightening torque: 10 Nm (7.5 ftlb.) -3 and 4- (camshaft housing, cylinder head, crankcase and oil pan).

Oil return line

39. Position oil feed housing of inlet camshaft and tighten - Tightening torque: 10 Nm (7.5 ftlb.).

Information:
If the camshaft timing gears and camshaft adjusters are removed completely, the diamond washers and fastening screws must be replaced!

40. Replace the diamond washer and fastening screw located underneath the camshaft adjuster and camshaft timing gear.

Diamond washer

41. Fit deflection rail -4-.

Deflection rail

Caution: Damage to the camshaft switch-over valve!
Malfunction.

- Do not turn camshaft switch-over valve.

42. Install camshaft switch-over valves - Tightening torque: 10 Nm (7.5 ftlb.). Figure shows procedure with timing-case cover fitted.

Fastening screw for camshaft switch-over valve

43. Fit timing drive mechanism. Fit guide rail of cylinder bank 5 - 8. Tighten the leaf spring of the oil pump tensioning rail at the same time.
44. Fit tensioning rail to cylinder bank 1 - 4.
45. Install timing chain. Position the chain on the crankshaft gear wheel and then fit it over all four camshaft timing gears. To do this, use both hands to carefully insert the camshaft adjuster and camshaft timing gear into the timing chain. Screw in fastening screws on the timing gears loosely to half a turn. Figure shows procedure with timing-case cover fitted. Screw in fastening screws on the timing gears loosely to half a turn.

Installing timing chain

46. Fit U-rail. Insert the U-rail into the timing drive mechanism from above. Tighten the four fastening screws.
47. Fit the short guide rails between the camshaft timing gears. Figure shows assembly with timing-case cover fitted.

Guide rails

48. Fit timing-case cover.
49. Place sealing ring over crankshaft using assembly sleeve.

Sealing ring with assembly sleeve

50. Tighten the two upper fastening screws (M6 x 50) and the lower fastening screws (M6 x 12) by hand.

Crankshaft sealing ring

51. Tighten the two upper fastening screws (M6 x 50) and the lower fastening screws (M6 x 12) by hand. Then tighten the screws crosswise. - Tightening torque: 10 Nm (7.5 ftlb.)

Crankshaft sealing ring

52. Pull assembly sleeve evenly off the sealing ring.

Assembly sleeve

Information:
If the sealing flange on the pulley is slightly rusted, polish the rust off with a special polishing pad (e.g. Never Dull).
If the sealing flange is badly corroded or contains deep grooves, replace it.

Information:
A feather key is inserted into the crankshaft. When fitting the pulley, ensure that the feather key slots into the groove in the pulley.
The key must not fall into the engine.

53. Fit crankshaft belt pulley.

Crankshaft belt pulley

54. Fit oil pan.

Measurement on the oil pan

55. Fit drive plate or flywheel.
56. Install chain tensioner with new sealing ring. - Tightening torque: 60 Nm (44 ftlb.)

Installation position of chain tensioner

Information:
To remove the play from the timing chain for the setting process, the crankshaft must be positioned approx. 45° in front of the TDC of cylinder 1 before turning!

57. Set the timing.
58. Install the camshaft housing cover on both cylinder rows.
59. Fit water pump.

Subsequent work

Subsequent work

1. Fit left additional assembly bracket -2- and right engine carrier -8-. There are still two dowel sleeves (not shown) on the additional assembly bracket.