Part 4
WM 1001Z2 Assembling V8 4.8-litre DFI engine as of October 2008
Camshafts, cylinder bank 1 to 4
36. Coat camshaft bearings with normal multipurpose grease or engine oil.
37. Insert bucket tappets into the cylinder head if necessary (bucket tappets for intake and outlet side have different diameters). The bucket tappets have a twist lock that fits into a guide groove in the cylinder head. Fit used bucket tappets at the same position.
38. Position vibration balancer with screw tightened by hand. Turn crankshaft to just before cylinder 1 TDC (prevents the valves from sitting on the piston when directly at TDC). Item 2
Staking bore 45 ° before TDC
Information
A data matrix coding is shown on the staking dihedron of the camshafts. This is a square black/white dotted marking used for electronic identification purposes during the production process. This marking can be used as an aid when inserting the camshafts into the cylinder head. All four camshafts press against the valves the least when the data matrix coding is facing upwards during installation.
39. Insert camshafts so that the minimum amount of pressure is exerted on the valve springs and coat bearing locations with normal multipurpose grease or engine oil. Position housings correctly and screw down. The housings are numbered and marked with E (intake) or A (outlet). Fit camshaft housings evenly and gradually, and slowly tighten to the specified tightening torque. The camshafts must not be strained or tilted. Outlet camshafts and intake camshafts (also bank-specific) cannot be used interchangeably because of the bearing locations and length.
Camshaft identification on V8 naturally aspirated engine M48/01
Camshaft housing identification
Camshaft mount, cylinders 5 to 8
40. Move both hydraulic valves for camshaft control into installation position and fit them. Item 5
Camshaft control
41. Insert oil vent line at the firewall side of cylinder 5 and screw it on. Grease sealing ring sparingly with Kluber Syntheso GLEP 1.
Vent line
42. Fit threaded peg for tensioning and guide rails. Items 1 and 2
Timing chain and chain guide
43. Fit guide rail with oil pump chain tensioning rail and pull locking pin (tensioning rail will be released).
44. Fit "U"-shaped deflection rail item 4.
Timing chain and sprockets
45. Fit tensioning rail and let it hang.
46. Fit both small guide rail pieces between the camshaft controller and sprocket.
47. Loosely fit camshaft controller and sprockets using screws (do not forget new diamond washer under the camshaft controllers).
48. Position timing chain and guide correctly over guide and tensioning rails.
49. Fill Loctite 5900 (000.043.204.35 status 04/07) first into the opening of the seal for the timing-case cover. Apply sealant as shown in the illustrations. Install the timing-case cover within 5 minutes.
Timing-case cover seals
Applying sealant (fill openings in metal seal with sealant)
50. Move timing-case cover with pre-fitted metal seals into installation position (carefully insert oil vent line, grease sealing ring with Kluber Syntheso GLEP 1 if necessary). When doing so, press the tensioning rail away from the sprocket at the timing chain using a screwdriver (second worker required). Position timing-case cover.
51. Fit the timing-case cover using four to six screws. Align timing-case cover with the edge of the lower part of the crankcase (realign using plastic hammer if necessary). Fit remaining screws. Check projection again with respect to the lower part of the crankcase and realign if necessary. The timing-case cover can be adjusted using a dial gauge, steel rule or by touch (projection of timing-case cover with respect to the lower part of the crankcase). It should not be possible to feel or measure any projection on either side of the timing-case cover.Example: Adjusting timing-case cover using a dial gauge
52. Insert the dial gauge into the universal gauge holder and position it so that the dial gauge has a preload of about 1 mm.
Adjusting preload
53. Set dial gauge scale to 0. To do this, place the dial gauge holder on a completely flat surface (e.g. crankcase) and turn the dial gauge scale until the pointer is at 0.
Setting dial gauge scale to zero
54. Measure offset. In order to do this, push with the holder starting from the lower part of the crankcase towards the timing-case cover (the foot of the dial gauge holder is not located on the same component as the dial gauge probe) and measure the offset. The timing-case cover must not be set back any more than 0.1 mm. A projection is not permissible.
Measuring offset
55. Align the timing-case covers by tapping lightly with a rubber hammer.
Aligning chain case lid
56. Then check the position of the timing-case cover again with the dial gauge.
Checking
57. Fit timing-case cover according to specifications. When doing so, do not forget any of the sheetmetal holders under the screws.
Tightening sequence for timing-case cover
58. Fit new joint flange between the vibration damper and timing-case cover. Align joint flange, fit screws and pull plastic sleeve.
Seal with plastic sleeve
Chain tensioner, joint flange
59. Turn the engine around. Oil pump is upright.
60. Lay sealing ring in the lower part of the crankcase.
61. Apply sealant to the oil guide housing as specified. Sealant should be applied thinly and evenly. Screw down within 5 minutes.
Applying sealant to oil guide housing
62. Position oil guide housing and align against transmission or projection of lower part of the crankcase. On the transmission side the oil guide housing must not project further than the crankcase. Make sure that the transmission can later be screwed evenly to the block. The oil guide housing can be adjusted in the same way as the timing-case cover (using a dial gauge, etc.).
63. Screw down oil guide housing. Tighten all screws evenly crosswise. see item 6 Do not forget screws between the oil guide housing and timing-case cover (four screws behind front vibration balancer, bores are currently overhead).
Oil guide housing with accessories
64. Equip intake manifold oil strainer with sealing ring and then fit it. Tighten all oil pipes. Replace sealing rings.
Oil lines on naturally aspirated engine (M48/01)
Oil lines, intake pipe on naturally aspirated engine M48/01
65. Push joint flange of the oil pressure control valve through the side oil pan opening via the oil pressure control valve and secure using two screws. Item 10 Fit oil level sensor (turn carefully when inserting) item 7
Oil guide housing with accessories
66. Fit lower oil pan and tighten evenly crosswise (the inserted seal can be reused provided it does not leak and is not damaged). Insert and fit oil drain plug with new sealing ring.
Oil pan
67. Turn the engine around.
68. Position vibration balancer with screw tightened by hand.
69. Set the timing. Follow procedure exactly. -> 150516 Setting camshaft timing on 4.8-litre DFI engines Procedures
70. Fit small side line brackets for the ATF lines.
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.
71. Tighten vibration balancer to the specified torque (use brace brace 9679/1 ). Make a mark between the screw and the vibration balancer using a water-resistant marker (continuous line from screw to vibration balancer). Mark a second line on the vibration balancer at 180° from the first marking. Tighten from first marking to the second marking (torque-angle tightening). For exact tightening specification, see legend for figure Pulleys - item 4
Supporting engine (illustration shows V8 4.5-litre engine supported on assembly support)
