Black
Yellow
Green
Blue

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Fastener Tightening Specifications
Component
Connecting rod bearing cap -o-connecting rod 1)

Nm
50 plus an
additional 90°
(¼ turn)
60 plus an
additional 90°
(¼ turn)
22
9

Drive plate crankshaft 1)
Idler roller for the ribbed belt-to-engine
Oil spray jet
Tensioner for the ribbed belt-to-engine 2)
- Bolt
- Bolt
2)

Engine –
4.0L CEUC

1)

22
55

Replace fastener(s).
For bolt tightening clarification, refer to ElsaWeb, Ribbed Belt Drive Overview,
items 1 and 2.

Vibration Damper, Tightening Specification

Step
1
2
3

Bolts
Arrow
Arrow
Arrow

Tightening Specification/Additional Turn
15 Nm in a diagonal sequence
22 Nm in a diagonal sequence
In a diagonal sequence, turn an additional 90°

Audi A6/S6 Quick Reference Specification Book

•

September 2013

77

Baffle Plate Tightening Specification

Step
1
2

78

Component
Tighten bolts 1 through 6 in sequence
Tighten bolts 1 through 6 in sequence

Audi A6/S6 Quick Reference Specification Book

Nm
5
an additional
90° (¼ turn)

•

September 2013

Engine –
4.0L CEUC

Guide Frame Tightening Specifications

Step
1
2
3
4
5
6
7

Bolts
1 through 10
11 through 20
1 through 10
1 through 10
11 through 20
11 through 20
Without numbering in
the illustration

Nm
30
30
50
an additional 90° (¼ turn)
50
an additional 90° (¼ turn)
9 Nm in a diagonal sequence

Audi A6/S6 Quick Reference Specification Book

•

September 2013

79

Spur Gear Unit Tightening Specifications

Tighten the bolts diagonally in the sequence -1 to 5- to 22 Nm.

Crankshaft Dimensions

Crankshaft with Crankshaft Bearing Journal Diameter 65 mm
Honing dimension in
mm

Crankshaft bearing
pin diameter

Basic dimension

65.000

Repair stage

65.750

– 0.022
– 0.042
– 0.022
– 0.042

Crankshaft
connecting rod
journal diameter
54.000
– 0.022
– 0.042
53.750
– 0.022
– 0.042

Crankshaft Dimensions

Crankshaft with Crankshaft Bearing Journal Diameter 67 mm
Honing dimension in
mm

Crankshaft bearing
pin diameter

Basic dimension

67.000

Repair stage

66.750

80

– 0.010
– 0.029
– 0.010
– 0.029

Crankshaft
connecting rod
journal diameter
54.000
– 0.022
– 0.042
53.750
– 0.022
– 0.042

Audi A6/S6 Quick Reference Specification Book

•

September 2013

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

New

Wear limit

0.20 to 0.35
0.20 to 0.40
0.20 to 0.40

0.80
0.80
0.80

New

Wear limit

0.035 to 0.085
0.005 to 0.045
0.020 to 0.055

0.200
0.150
0.200

Engine –
4.0L CEUC

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

Piston and Cylinder Dimensions
Honing dimension in
mm
Nominal dimension
Repair stage
1)

2)

Piston diameter

Cylinder bore
diameter
84.510 ± 0.005 2)
84.610 ± 0.005 2)

84.490 1)
84.590 1)

Dimension without graphite coating (thickness 0.01 mm). The graphite coating
wears away.
Measure 50 mm inside the cylinder bore.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

81

Cylinder Head, Valvetrain – 4.0L CEUC
Fastener Tightening Specifications
Component
Balance shaft
Bracket for idler sprocket to engine 1)
Camshaft adjuster for exhaust camshaft to camshaft 1)
Camshaft adjuster for intake camshaft to camshaft 1)
Camshaft adjustment valve to camshaft housing
Chain tensioner to engine 1)
Chain tensioner with glide track to engine 1)
Connection for coolant to right timing chain cover
Engine lifting eye to engine
Glide track to engine 1)
Intake/exhaust camshaft adjuster to camshaft housing
Mounting pin for left camshaft timing chain drive sprocket
to bearing plate 1)
Mounting pin for the right camshaft timing chain drive
sprocket to engine 1)
Mounting pin for idler sprocket to engine
1)

Nm
9
5 plus an
additional 90°
(¼ turn)
80 plus an
additional 90°
(¼ turn)
80 plus an
additional 90°
(¼ turn)
5
5 plus an
additional 90°
(¼ turn)
5 plus an
additional 90°
(¼ turn)
9
22
17 plus an
additional 90°
(¼ turn)
5
5 plus an
additional 90°
(¼ turn)
20 plus an
additional 45°
(⅛ turn)
42

Replace fastener(s).

Compression Checking Specifications
Compression pressure
New
Wear limit
Maximum difference between cylinders

82

Audi A6/S6 Quick Reference Specification Book

Bar pressure
10.0 to 15.0
9.0
3.0

•

September 2013

Engine –
4.0L CEUC

Valve Dimensions

Dimension
Diameter a
mm
Diameter b
mm
c
mm
α

∠°

Intake valve
33.85 ± 0.10
5.98 ± 0.007
103.97 ± 0.20

Exhaust valve
28.0 ± 0.1
5.935 ± 0.007
101.87 ± 0.2

45

45

NOTE: Intake and exhaust valves must not be
refaced by grinding. Only lapping is permitted.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

83

Left Timing Chain Cover Tightening Specifications

Step
1
2
1)

Component
Tighten bolts 1 through 8 in sequence
Tighten bolts 1 through 8 in sequence 1)

Nm
5
an additional
90° (¼ turn)

Replace fastener(s)

NOTE: The mount -arrow- is affixed with the timing chain guard.

84

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Engine –
4.0L CEUC

Right Timing Chain Cover Tightening Specifications

Step
1
2
1)

Component
Tighten bolts 1 through 8 in sequence
Tighten bolts 1 through 8 in sequence 1)

Nm
5
an additional
90° (¼ turn)

Replace fastener(s)

NOTE: Brackets A and B are connected with the timing chain cover.

Audi A6/S6 Quick Reference Specification Book

•

September 2013

85

Lower Timing Chain Cover Tightening Specifications

Step

Nm

Tighten the bolts (Æ)

5

2

Tighten bolts 2 through 8 in a diagonal
sequence
Tighten the bolts (Æ)

8

3
4

86

Component

1

8

5

Tighten bolts 2 through 8 in a diagonal an additional 90° (¼ turn)
sequence
an additional 90° (¼ turn)
Tighten the bolts (Æ)

6

Tighten bolts 1

Tighten for the power
steering pump, refer to
ElsaWeb, Suspension
Wheels, Steering

Audi A6/S6 Quick Reference Specification Book

•

September 2013

Engine –
4.0L CEUC

Cylinder Head Loosening

Loosen the cylinder head bolts in the sequence -1 to 10

Audi A6/S6 Quick Reference Specification Book

•

September 2013

87

Cylinder Head Tightening Specifications

NOTE: Replace any bolts that were tightened with an additional turn.
The cylinder head for cylinder bank 2 (left) is shown in the illustration.
Step

88

Component

Nm

1

Tighten bolts 1 through 10 in sequence

Hand-tighten

2

Tighten bolts 1 through 10 in sequence

30

3

Tighten bolts 1 through 10 in sequence

60

4

Tighten bolts 1 through 10 in sequence

5

Tighten bolts 1 through 10 in sequence

6

Arrows

an additional 90°
(¼ turn)
an additional 90°
(¼ turn)
10

7

Arrows

Audi A6/S6 Quick Reference Specification Book

an additional 90°
(¼ turn)

•

September 2013

Engine –
4.0L CEUC

Camshaft Guide Frame Tightening Specifications