Part 1
Tightening torques, tightening sequences, assembly overviews for V8 4.8 l DFI naturally aspirated and turbo engine as of October 2008
Cylinder head screws can be re-used
Information
Component changes for model year 2009 as of October 2008
Always read the information concerning modified tightening specifications and component changes relating to repairs provided for specific engine numbers in the Information section!
Technical values
Overview
Information
The tightening steps in the tightening sequences relate to tightening screws uniformly, i.e. all affected screws must first be tightened uniformly to the first torque value, then all screws are tightened one stage further, and so on.
Replace all O-rings following removal!
The torques in the table below generally apply to screws that are not specifically listed
The bolt quality is indicated on the screw head at the top as a decimal number, e.g. "8.8" or "12.9".
Aluminium screws
Engine - Crankcase, suspension
Upper part of crankcase
1 - Upper part of crankcase
2 - Lid
3 - Sealing ring
4 - Screw plug on upper part of crankcase - Tightening torque: 75 Nm (56 ftlb.)
5 - Dowel sleeve
6 - Oil spray jet
7 - Screw, M6 x 16 - Tightening torque: 10 Nm (7.5 ftlb.)
A - Direction of travel
Lower part of crankcase
1 - Lower part of crankcase
2 - Straight pin, 6 x 18
3 - O-ring
4 - Sealant application - Doboseal 224N (999.915.573.43, status 09/08)
5 - Thrust-bearing screw M11; tighten screws within 5 minutes; observe tightening sequence. Initial tightening: 30 Nm (22 ftlb.) - Torque angle: 90 degrees
6 - Thrust-bearing screw M10; tighten screws within 5 minutes; observe tightening sequence. Initial tightening: 22 Nm (16 ftlb.) - Torque angle: 60 degrees
7 - Aluminium screw, M8 x 70; (cross bolt connection); always use new aluminium screws; observe tightening sequence as for steel screws - Initial tightening: 10 Nm (7.5 ftlb.) and - Final tightening: 90 degrees
8 - Screw, M8 x 35 - Tightening torque: 23 Nm (17 ftlb.)
9 - Screw, M8 x 50 - Tightening torque: 23 Nm (17 ftlb.)
10 - Dowel sleeve
A - Direction of travel
Sealant application
1 - Wipe off sealant residues after fitting
A - Direction of travel
Tightening sequence for thrust-bearing screws
1 through 20 - Tightening sequence for M11 and M10 screws - Observe different torques!
A - Direction of travel
Tightening sequence for securing lower part of crankcase to upper part of crankcase (cross bolt connection)
Left bracket for auxiliary units and engine mounting
1 - Bracket for auxiliary units/engine mounting
2 - Screw, M10 x 45 - Tightening torque: 65 Nm (48 ftlb.)
3 - Hydraulic mount, left
4 - Engine carrier
5 - Screw, M10 x 65 - Tightening torque: 60 Nm (44 ftlb.)
6 - Dowel sleeve
7 - Nut, M12 x 1.5 - Tightening torque: 75 Nm (56 ftlb.)
Right bracket for auxiliary units and engine mounting
1 - Engine carrier, cylinders 1 to 4
2 - Screw, M10 x 45 - Tightening torque: 65 Nm (48 ftlb.)
3 - Hydraulic mount, right
4 - Engine carrier
5 - Screw, M10 x 65 - Tightening torque: 60 Nm (44 ftlb.)
6 - Nut, M12 x 1.5 - Tightening torque: 75 Nm (56 ftlb.)
7 - Bores for screws, M10 x 45
A - Installation view of engine carrier on crankcase
Vent line
1 - Vent line to cylinder head/crankcase/oil pump
2 - O-ring
3 - Screw, M6 x 12 - Tightening torque: 10 Nm (7.5 ftlb.)
4 - Check valve
A - Direction of travel
Oil mist separator for positive crankcase ventilation (M48/51 turbo engine)
1 - Engine ventilation - Tightening torque: 10 Nm (7.5 ftlb.)
2 - Engine ventilation line
3 - Tank ventilation
4 - Holder - Initial tightening: 4 Nm (3 ftlb.) and - Final tightening: 90 degrees
Oil mist separator for positive crankcase ventilation (M48/01 naturally aspirated engine)
1 - Engine ventilation - Tightening torque: 10 Nm (7.5 ftlb.)
2 - Engine ventilation line
3 - Screw, M6 x 12 - Tightening torque: 10 Nm (7.5 ftlb.)
4 - Lid with seal
5 - Engine ventilation line
6 - Line
7 - Tank ventilation with holder - Initial tightening: 4 Nm (3 ftlb.) and - Final tightening: 90 degrees
Positive crankcase ventilation, M48/51 Turbo
1 - Check valve
2 - Engine ventilation line
3 - Positive crankcase ventilation line to pressure pipe
4 - Holder (see Belt tensioner/belt drive)
5 - Line
Positive crankcase ventilation (PCV), M48/51 Turbo
1 - Ventilation pipe with sealing ring (holder to timing-case cover) - Initial tightening: 4 Nm (3 ftlb.) and Final tightening: 90 degrees
2 - Screw, M6 x 12 - Tightening torque: 10 Nm (7.5 ftlb.)
A - Installation view of ventilation pipe
Engine - Crankgear, pistons
Crankshaft
1 - Crankshaft
2 - Straight pin, 6 x 20
3 - Spring, 5 x 6.5
4 - Thrust washer (grooves facing out)
5 - Main bearing shell, upper
6 - Main bearing shell, lower
7 - Shaft sealing ring - Do not touch sealing ring lip! Clean crankshaft flange and oil lightly
8 - View of crankshaft flange
9 - Crankshaft bearing classification (four types) Y Yellow; B Blue, R Red; N Green - (example: YYYYY-BBBB; 5 main shaft bearings with yellow marking, 4 double (8) connecting rod bearings with blue marking) - For numbering, see A
A - Direction of travel (main bearing 1 is the first in direction of travel against output)
Belt drive
1 - Deflection roller - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
2 - Hydraulic belt tensioner; tensioner to lever - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.). tensioning roller to tensioning lever - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
3 - Screw, M8 x 96; complete lever to timing-case cover and cylinder head - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.). belt tensioner and timing-case cover to bracket - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
4 - Deflection roller - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
5 - Dual poly V-belt
Piston, connecting rod
1 - Piston-ring set; oil with engine oil; TOP marking facing upwards; oil scraper ring down
2 - Piston; different on naturally aspirated and turbo engines; combustion chamber recess facing center of engine; left and right different; direction of travel arrow in direction of travel
3 - Piston-pin circlip (positioned at 6 o'clock or 11 o'clock)
4 - Piston pin; oil
5 - Connecting rod
6 - Connecting rod bolt; replace as it must be tightened in the plastic area; oil bolt - Tightening torque: 8 Nm (6 ftlb.)+2 Nm (+1.5 ftlb.) - Tightening torque: 20 Nm (15 ftlb.) - Tightening torque: 40 Nm (30 ftlb.) - Torque angle: 90 degrees
7 - Connecting rod bearing shells; oil with engine oil
Connecting-rod assembly, bearing shells
A - View A (identification area for connecting-rod number; fit connecting rod with identification area facing exhaust side; markings on rod and cap must be on the same side)
B - View B (fit bearing shells flush and press in by hand)
C - View C (fit bearing shells flush and press in by hand)
Piston classification
1 - Inspection stamp (supplier)
2 - Arrow marking in direction of travel
3 - Porsche short numeric code without main or middle number
4 - Cylinder bank identification
5 - Marking area for weight group
6 - Marking area for dimension group
7 - Barcode 128 (short numeric code (without main group) and weight group)
8 - Direction of travel arrow
9 - Short numeric code (supplier)
Radial shaft seal
1 - Radial shaft seal (use protection cap for radial shaft seal for fitting; only fit when crankcase is screwed on)
2 - Crankcase
3 - Crankshaft
4 - Radial shaft seal (sectional view)
A - Direction of travel
Pulleys
1 - Water pump pulley
2 - Screw, M8 x 16 - Tightening torque: 23 Nm (17 ftlb.)
3 - Vibration damper
4 - Screw, M18 x 1.5 x 72; use new screw; - Tightening torque: 20 Nm (15 ftlb.) - Tightening torque: 50 Nm (37 ftlb.) - Tightening torque: 100 Nm (74 ftlb.) - Torque angle: 180 degrees
5 - Pulley on power-steering pump
6 - Screw, M8 x 16 - Tightening torque: 23 Nm (17 ftlb.)
7 - Tandem pump pulley
Engine - Cylinder head, valve control
Information
The eyelets must not be inadvertently secured using aluminium screws! - Aluminium screws would break and the suspended engine would fall down!
Valves (cylinder bank 5 to 8)
1 - Intake valve
2 - Valve-seat ring (intake)
3 - Valve guide
4 - Lower valve-spring plate (intake)
5 - Valve stem seal
6 - Set of valve springs (intake)
7 - Upper valve-spring plate (intake)
8 - Valve collet
9 - Upper valve-spring plate (outlet)
10 - Set of valve springs (M48/51 outlet); outlet valve spring (M48/01)
11 - Lower valve-spring plate (outlet)
12 - Valve-seat ring (outlet)
13 - Outlet valve
Cylinder head 1 to 4
1 - Cylinder head 1 to 4
2 - Cylinder head gasket 1 to 4
3 - Screw, M8 - Tightening torque: 23 Nm (17 ftlb.)
4 - Lid
5 - Stopper
6 - Stopper
7 - Restrictor for valve lift control - Tightening torque: 1.5 Nm (1.0 ftlb.)
8 - Cylinder-head screws
9 - Spark plug; when reinstalled - Tightening torque: 25 Nm (19 ftlb.)+3 Nm (+2 ftlb.) if fitting new spark plugs - Tightening torque: 30 Nm (22 ftlb.)+3 Nm (+2 ftlb.)