Audi V8 Instructions de montage
Service.
For internal use only
All rights reserved. Subject to
technical modifications.
AUDI AG
Abteilung I/VK-5
D-85045 Ingolstadt
Fax 0841/89-36367
940.2810.36.20
Technical status 02/99
Printed in Germany
The V8-5V Engine
Construction Features and Functions
Self-Study Programme 217
217
217
2
SSP217_048
AUDI has been producing advanced 8-cylinder
engines since 1988. Their capacity has increased
from 3.6 l to 4.2 l.
The V8 engine in combination with Aluminium
Space Frame technology was the technical basis
forAudi's breakthrough into the luxury class.
Steps to enhance the value of the Audi A8 have
included the redesign of the V8 engine.
The new V8-5V engines are now also available for
the Audi A6 model range.
3
Engine - Motronic Subsystems
Variable intake manifold ...................................................... 27
Secondary air system ........................................................... 32
Content
Introduction
Engine - Mechanics
Crankgear .............................................................................. 6
Engine mounting .................................................................. 9
Engine lubrication ................................................................ 10
Cooling circuit ....................................................................... 16
Cylinder head
Five-valve technology ............................................. 19
Roller rocker ............................................................ 20
Camshaft adjuster .................................................. 22
Toothed-belt drive; cylinder-head seal ................. 24
Cylinder-head cover seal ........................................ 25
Exhaust manifold .................................................... 26
Technical data ....................................................................... 5
The self-study programme is not a repair manual!
The self-study programme provides you with information
concerning the engine's construction features and functions.
New! Caution!
Important!
Page
When carrying out maintenance and repair work, it is essential
to use the latest technical literature.
Engine Management
System overview ................................................................... 36
Function diagram ................................................................. 38
Quick-start functions
Camshaft position sensor ...................................... 40
Engine run-down sensor ........................................ 41
Electronic throttle function ................................................. 42
CAN bus interfaces ............................................................... 44
Additional signals / interfaces ............................................ 46
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4
New features
– Five-valve cylinder head with roller rocker
– Camshaft adjustment
– 3-stage variable intake manifold
– Engine management system, Bosch ME 7.1
– Electro-hydraulic engine mounting
Modifications
– to crankcase and crankgear
– to oil circuit
– to cooling circuit
V8-5V Engines
Introduction
SSP213_073
Major modifications were made to the
V8 engines during the course of further
development.
Emphasis was placed on the following
development objectives:
– compliance with future exhaust-emission
regulations
– reduction of fuel consumption
– increase in torque and power
– improvement of comfort and convenience
– reduction of engine weight
– increased use of shared components for
the AUDI engine series.
The following new features and modifications
have been incorporated in the V8 4-valve
engine.
5
Technical data
The specified power data is only
possible if 98 RON fuel is used.
A reduction in power output must be
expected if 95 RON fuel is used.
3.7 l V8-5V engine
4.2 l V8-5V engine
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SSP217_004
SSP217_005
Torque (Nm)
Speed (rpm)
Power output (kW)
Torque (Nm)
Speed (rpm)
Power output (kW)
3.7 l 4.2 l
Engine code AQG AQF (A8)
ARS (A6)
Design V8 engine with 90
o
V angle
Capacity 3697 cm
3
4172 cm
3
Power output 191 kW
260 hp
at
6000 rpm
228/220 kW
310/300 hp
at
6000 rpm
Specif. output 51.6 kW/l
70.3 hp/l 54.6 kW/l
74.3 hp/l
Torque 350 Nm at
3200 rpm 410 Nm at
3000 rpm
Specif.
torque 94.7 Nm/l 98.3 Nm/l
Bore 84.5 mm 84.5 mm
Stroke 82.4 mm 93.0 mm
Compression
ratio 11:1 11:1
Weight 198 kg 200 kg
Engine
management Motronic ME 7.1
Fuel 98/95 RON
Firing
sequence 1 - 5 - 4 - 8 - 6 - 3 - 7 - 2
Exhaust-emis-
sion standard EU 3
6
Engine - Mechanics
Crankgear
The crankcase has been adapted to the
modifications made to the oil supply system
and cooling circuit.
Cracked-steel conrods have been used forthe
3.7 l engine since 1995 and are now also
being used for the 4.2 l engine.
The conrods are shared components used in
both the 2.4 l and 2.8 l engine.
SSP217_054
SSP217_006
7
Owing to the design of the valve recesses, the
pistons are specificallyintended for use in the
appropriate cylinder bank only.
SSP217_055
SSP217_002
8
Engine - Mechanics
The locking mandrel (V.A.G 3242) used for the
V6 engines is also used for locking the
crankshaft. It is applied to the crank web of
the 4th cylinder and is used for basic engine
adjustment and also as a counterhold for
loosening and tightening the central bolt of
the crankshaft.
SSP217_009
The 5th cylinder must be set to
ignition TDC.
SSP217_007
Wide, milled ventilation recesses above the
thrust bearings reduce pumping losses.
Bolts are also inserted at the side of the two
front crankshaft bearing caps to improve
running smoothness
(see SSP 198, page 6).
9
The central bolt does not have to be
unscrewed for the vibration damper to be
removed.
The marking indicates the ignition TDC of the
5th cylinder.
SSP217_050
Central bolt
Marking
Engine mounting
To enhance driving comfort, hydraulic engine
mounts with electrical activation are used for
the 8-cylinder engines.
They function in the way as described in
SSP 183/16.
The mounts are activated by the engine
control unit according to engine speed and
vehicle speed.
Electrical connection
SSP217_039
10
Engine - Mechanics
SSP217_010
A duocentric oil pump driven by the cranks-
haft via a chain replaces the previously used
external gear oil pump.
The duocentric oil pump extends deep into
the oil sump. The low suction height means
that the oil pressure can build up quickly,
especially with cold-starts.
The oil-pressure control valve is located in the
oil pump housing. The “diverted“ oil is led off
to the intake side of the oil pump. This helps
optimise the level of efficiency.
In the intake spindle shafts, there are 5 oil
bores per triple roller rocker. Three oil bores
each supply one hydraulic tappet. Two oil
bores supply the oil-spray bores integrated in
the roller rocker to lubricate the rollers. The
oil-spray bores are only opened when the
roller rockers are actuated. This results in a
reduction of the amount of oil required in the
cylinder head.
Oil-level sensor
Triple roller rocker
The roller rockers are described on
pages 20 and 21.
Engine lubrication
Ce manuel convient aux modèles suivants
2
Table des matières
Autres manuels Audi Moteur
