Turbocharger Tightening Specifications

Step
1
2
3
4

38

Component
Tighten bolts 1 through 5 in sequence
Tighten bolts 1 through 5 in sequence
Tighten bolts 1 through 5 in sequence
Tighten bolts 1 through 5 in sequence

Audi A6/S6 Quick Reference Specification Book

Nm
5
12
16
25

•

September 2013

Exhaust System – 2.0L CAED
Fastener Tightening Specifications
Component
Bracket to secondary air injection pump motor nut
Catalytic converter nut 1)
Clamp for exhaust tailpipe
Connection bolt
Exhaust tailpipe clamp
Front clamping sleeve nut
Front muffler nut 1)
Heat shield bolt
Secondary air pipe bolt
Secondary air injection solenoid valve 2)
Rear clamping sleeve nut
Suspended mount
1)

Replace fastener(s).
For bolt tightening clarification, refer to ElsaWeb, Secondary Air Injection System
Overview items 19 and 21.

Engine –
2.0L CAED

2)

Nm
9
20
23
9
23
23
20
23
23
9
19
23
23

Audi A6/S6 Quick Reference Specification Book

•

September 2013

39

Fuel Injection and Ignition – 2.0L CAED
Technical Data
Engine data
Idle speed cannot be adjusted, it is regulated by idle
stabilization
Engine speed limitation via fuel injector shut-off
Ignition timing is regulated by control module. It is not
possible to adjust the ignition timing.
Fuel pressure Fuel supply pressure up to high
pressure pump (produced as needed by
an electric fuel pump in the fuel tank).
Fuel high pressure line (produced by a
mechanical single-piston pump)
Ignition sequence

2.0L Turbo FSI
engine
640 to 800 RPM
6500 RPM

3.0 to 10.5
Bar pressure
30 to 150
Bar pressure
1-3-4-2

Fastener Tightening Specifications
Component
Air guide to air guide
Camshaft Position (CMP) sensor
Engine Speed (RPM) sensor
Fuel pressure sensor 2)
Fuel supply line connection on the fuel rail 1)
Fuel supply line connectors 1)
Fuel supply line union nut
High pressure fuel line
High pressure pump
Intake Air Temperature (IAT) sensor
Intake manifold
Intake manifold support bolt
Intake manifold support nut
Knock Sensor (KS)
Oxygen Sensors (O2S)
Screw-type clamps 9 mm Wide
Screw-type clamps 13 mm Wide
Spark plug
TThrottle valve control module to intake manifold
1)
2)

Nm
1.5
10
4.5
27
40
40
27
20
20
9
10
23
10
20
55
3.4
5.5
30
9

Replace fastener(s).
Coat the threads with clean engine oil.

40

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Engine Mechanical – 3.0L CTUA
Engine –
3.0L CTUA

General, Technical Data
Engine Number Location

The engine number (engine code and serial number) is
located on the top front of the cylinder block, below the
right cylinder head (Æ). Engine codes beginning with C are
four-digit. The first 3 digits of the engine code indicate the
displacement and the mechanical structure of the engine.
The fourth digit describes the engine output and torque.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

41

Engine Data
Code letters
CTUA
Displacement
liter
2.995
Output
kW at RPM
228 @ 5500 to 6500
Torque
Nm at RPM
440 @ 2900 to 4500
Bore
diameter mm
84.5
Stroke
mm
89.0
Compression ratio
10.5
RON
at least
95 1)
Fuel injection and ignition system
Simos
Ignition sequence
1-4-3-6-2-5
Exhaust Gas Recirculation (EGR)
No
Turbocharger, Supercharger
Supercharger
Knock control
2 sensors
Charge air cooler
Yes
Oxygen Sensor (O2S) regulation
2 sensors before catalytic converter
2 sensors after catalytic converter
Variable valve timing
Intake
Variable intake manifold
No
Secondary Air Injection (AIR) system
Yes
Valve per cylinder
4
1)

Unleaded RON 91 is also permitted but performance is reduced.

42

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Fastener Tightening Specifications
Component
Bolts and nuts

Engine mount 1)

Fastener
size
M6
M7
M8
M10
M12
-

Engine mount plate
Engine support 2)

-

Heat shield
Subframe
1)
2)

3)

Nm
9
15
20
40
65
90 plus an
additional 90°
(¼ turn)
20
20
40
10
55

Replace fastener(s).
For bolt tightening clarification, refer to ElsaWeb, Subframe Mount Overview, items
4 and 5.
Replace in pairs.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

43

Engine –
3.0L CTUA

Engine Assembly – 3.0L CTUA

Crankshaft, Cylinder Block – 3.0L CTUA
Allocation of Crankshaft Bearing
Shells for Cylinder Block

Bearing shells with the correct thickness are allocated to the
cylinder block in the factory. Colored dots on the sides of the
bearing shells identify the bearing shell thickness. Allocation
of the bearing shells to the cylinder block is marked by a
letter on the respective bearing on the guide frame.
Letter on guide frame
R
G
B
S

44

Color of bearing
Red
Yellow
Blue
Black

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Engine –
3.0L CTUA

Allocation of Crankshaft Bearing
Shells for Guide Frame

Bearing shells with the correct thickness are allocated to the
guide frame at the factory. Colored dots on the sides of the
bearing shells identify the bearing shell thickness. Allocation of
the bearing shells to the guide frame is marked on the flywheel
flange of the crankshaft by a row of letters. The first letter
represents bearing 1, the second letter is for bearing 2, etc.
Letter on guide frame
R
G
B
S

Audi A6/S6 Quick Reference Specification Book

Color of bearing
Red
Yellow
Blue
Black

•

September 2013

45

Fastener Tightening Specifications
Component
Connecting rod 1, 5)

Nm
50 plus an
additional 90°
(¼ turn)
60 plus an
additional 90°
(¼ turn)
9
9
9
40
40
40
20 plus an
additional 90°
(¼ turn)

Drive plate 1)
Locking bolt
Oil pressure regulation valve
Piston cooling oil spray jet 4)
Ribbed belt idler roller 3)
Ribbed belt idler roller 2)
Ribbed belt tensioning damper
Vibration damper 1)

1)
2)

3)

4)
5

Replace fastener(s).
For bolt tightening clarification, refer to ElsaWeb, Auxiliary Component Bracket
Ribbed Belt Drive Overview item 4.
For bolt tightening clarification, refer to ElsaWeb, Supercharger Ribbed Belt Drive
Overview, item 6.
Insert the bolt with locking compound
Lubricate the thread and contact surface.

46

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Engine –
3.0L CTUA

Ribbed Belt Sealing Flange Tightening Specification

Component
Tighten bolts (Æ) in a diagonal sequence

Audi A6/S6 Quick Reference Specification Book

Nm
9

•

September 2013

47

Guide Frame Tightening Specifications

Step
1
2
3
1)

Component
Tighten bolts 1 through 16 in sequence 1)
Tighten bolts 1 through 16 in sequence

Nm
50
an additional
90° (¼ turn)
23

Replace and tighten bolts 17 through 31 in
sequence

Replace fastener(s).

48

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Crankshaft Dimensions
Crankshaft bearing
pin diameter

Basic dimension

65.000

Crankshaft
connecting rod
journal diameter
56.000
– 0.022
– 0.042

– 0.022
– 0.042

Engine –
3.0L CTUA

Honing dimension in
mm

Piston Ring End Gaps
Piston ring dimensions
in mm
1st compression ring
2nd compression ring
Oil scraping ring
1)

New

Wear limit

0.20 to 0.30
0.50 to 0.70
0.25 to 0.50

0.80
0.80
– 1)

Not determined.

Piston Ring Clearance
Piston ring dimensions
in mm
1st compression ring
2nd compression ring
Oil scraping ring

New

Wear limit

0.04 to 0.08
0.03 to 0.07
0.02 to 0.06

0.20
0.20
0.15

Piston and Cylinder Dimensions
Honing dimension in
mm
Basic dimension
1)

Piston diameter

Cylinder bore
diameter
84.51

84.49 1)

Dimension without graphite coating (thickness 0.02 mm). The graphite coating
wears away.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

49

Cylinder Head, Valvetrain – 3.0L CTUA
Fastener Tightening Specifications
Component
Balance shaft
Balance shaft chain sprocket 1)

Nm
60
15 plus an
additional 90°
(¼ turn)
13
5
10 plus an
additional 45°
(⅛ turn)
8 plus an
additional 45°
(⅛ turn)
5 plus an
additional 60°
(1⁄6 turn)
80 plus an
additional 90°
(¼ turn)
10 plus an
additional 90°
(¼ turn)
10 plus an
additional 90°
(¼ turn)
80 plus an
additional 90°