Audi V8 Service

Self-study programme 217

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Service.

The V8-5V Engine

Construction Features and Functions

Self-Study Programme 217

For internal use only

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Page 1 Service. The V8-5V Engine Construction Features and Functions Self-Study Programme 217 For internal use only...
Page 2 Space Frame technology was the technical basis for Audi's breakthrough into the luxury class. SSP217_048 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...
Page 3: Table Of Contents
Content Page Introduction Technical data ............... 5 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 ........
Page 4: Introduction
Introduction V8-5V Engines SSP213_073 Major modiﬁcations were made to the New features V8 engines during the course of further – Five-valve cylinder head with roller rocker development. – Camshaft adjustment Emphasis was placed on the following – 3-stage variable intake manifold development objectives: –...
Page 5: Technical Data
Technical data 3.7 l V8-5V engine 3.7 l 4.2 l Engine code AQF (A8) ARS (A6) Design V8 engine with 90 V angle Capacity 3697 cm 4172 cm Power output 191 kW 228/220 kW 260 hp 310/300 hp 6000 rpm 6000 rpm Specif.
Page 6: Engine - Mechanics
Engine - Mechanics Crankgear SSP217_054 The crankcase has been adapted to the modiﬁcations made to the oil supply system and cooling circuit. Cracked-steel conrods have been used for the 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.
Page 7 SSP217_055 Owing to the design of the valve recesses, the pistons are speciﬁcally intended for use in the appropriate cylinder bank only. SSP217_002...
Page 8 Engine - Mechanics 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). SSP217_007 The locking mandrel (V.A.G 3242) used for the V6 engines is also used for locking the crankshaft.
Page 9: Engine Mounting
Marking 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 Engine mounting To enhance driving comfort, hydraulic engine mounts with electrical activation are used for the 8-cylinder engines.
Page 10: Engine Lubrication
Engine - Mechanics Engine lubrication Triple roller rocker SSP217_010 Oil-level sensor A duocentric oil pump driven by the cranks- In the intake spindle shafts, there are 5 oil haft via a chain replaces the previously used bores per triple roller rocker. Three oil bores external gear oil pump.
Page 11 Cylinder bank 1 Cylinder bank 2 Throttle Oil retention valves Throttle Spray jet valve Camshaft Oil ﬁlter module Oil pressure control valve SSP217_011 Filter element Oil sump Oil cooler Bypass valves Duocentric oil pump Slight modiﬁcations have been made to the oil circuit in the cylinder heads.
Page 12 Engine - Mechanics Oil ﬁlter module (A8) Oil cooler bypass valve Coolant supply Alternator mount (part of oil module) Coolant return Oil return Oil pressure switch Oil supply SSP217_013 Drain plug Filter bypass valve The oil ﬁlter module contains the oil ﬁlter As was previously the case, the oil cooler is and oil cooler.
Page 13 Oil ﬁlter module (A8) Coolant Oil duct return Coolant supply Oil cooler bypass valve (from engine) Plastic con- nection Oil return (to engine) Oil cooler Oil supply (from engine) Oil cooler supply Engine oil Oil cooler return O-ring seal SSP217_014 Coolant supply Sealing surface Coolant...
Page 14 Engine - Mechanics Duocentric oil pump External runner Internal gear Oil pressure control valve The pitch of the internal gear and the external runner has no functional signiﬁcance and is determined by production engineering factors. To ensure that the assembly functions correctly, the narrow gears must not run together on the same plane.
Page 15 Notes...
Page 16: Cooling Circuit
F18/F54 SSP217_015 The ﬂow direction of the coolant has been changed in the new V8 5-valve engines. As with the V6 engines, the coolant leaving the cylinder heads merges in the rear coolant pipe from where it is then led off to the...
Page 17 The new coolant pipe alters the coolant ﬂow in the „small“ cooling circuit. New coolant pipe to cylinder head (small cooling circuit) Coolant pipe (return for heater, oil cooler and expansion tank) Oil cooler return Breather pipe SSP217_016 (to expansion tank) to vehicle radiator Coolant return Coolant temperature...
Page 18 Engine - Mechanics Previous design: The coolant thermostat is connected to the “small coolant circuit“ via two holes in the cylinder crankcase (see Fig. 217_017). The holes are directly connected to the cylinder-head water jacket (1st cylinder) and the water jacket of the cylinder crankcase. The heated coolant ﬂows from the 1st cylinder to the coolant thermostat.
Page 19: Cylinder Head
SSP217_020 Five-valve technology is now also being used The rockers are made of die-cast aluminium in the V8 engines. in order to keep inertia forces as low as possible. As a result, the valvegear is able to Roller rockers are being used for the ﬁrst time function reliably at engine speeds of up to in the enhanced ﬁve-valve cylinder head.
Page 20: Roller Rocker
Engine - Mechanics Roller rocker Exhaust valve Single cam Twin roller rocker SSP217_023 Roller located between rocker arms Spindle shaft, also used to supply oil Oil spray hole Exhaust valve 20.2˚ SSP217_022 Every valve has a hydraulic valve lifter which The two exhaust valves are actuated by a twin is integrated in the rocker.
Page 21 Inlet valve Double cam Hydraulic valve lifter with slide pad (hydraulic valve tappet) Spindle shaft SSP217_025 Triple roller rocker Oil duct Inlet valve 2 14.9˚ The three inlet valves are actuated via a triple roller rocker. A double cam actuates the rocker by means of two rollers between the rocker arms.
Page 22: Camshaft Adjuster
Slide pad adjuster SSP217_026 The camshaft adjustment system, a feature In the case of the new V8 engines, an incorporated in Audi's current range of interlock function and an oil reservoir were engines, is also used in the new generation of added to the proven system during the V8-5V engines.
Page 23 Lubrication and breather hole Engine off: Oil supply If there is no oil pressure, Locking pin a spring-loaded locking pin is pushed into the detent slot of the Oil return adjusting piston. The Oil reservoir adjusting piston is then locked. Adjusting piston SSP217_027 Engine start:...
Page 24: Toothed-Belt Drive; Cylinder-Head Seal
Engine - Mechanics Toothed-belt drive The toothed-belt drive is identical to that of the V6-5V engine. The V8-5V engine is also ﬁtted with a stabilising roller. The components are largely identical to those of the V6-5V engine. Stabilising roller Eccentric roller...
Page 25: Cylinder-Head Cover Seal
Cylinder-head cover seal Seal Decoupling element (long) Cylinder head Spacer sleeve cover Proﬁled rubber grommet Seal - cylinder head cover SSP217_040 Decoupling element Spacer sleeve (short) The thin-wall cylinder head covers are made The above-mentioned measures means that of a die-cast magnesium alloy. A seal concept, the cylinder head cover is not directly coupled which decouples the cylinder head cover from with the cylinder head.
Page 26: Exhaust Manifold
Engine - Mechanics Exhaust manifold Manifold ﬂange (left-hand cyl. bank) Connection for front exhaust pipe Outer shell Individual pipes reshaped for internal high pressure Cloverleaf arrangement SSP217_036 The pipe sections and assembly of the air- This protects the individual cylinders gap-insulated exhaust manifold have been effectively against annoying exhaust modiﬁed.
Page 27: Engine - Motronic Subsystems
(inlet side) stage 2 Increasing torque by means of variable intake manifolds is a tradition at Audi. A three-stage variable intake manifold made of a die-cast magnesium alloy, a further development of previous concepts, is to be used for the ﬁrst time.
Page 28 Engine - Motronic Subsystems Stage 1 Intake manifold ﬂap Lower speed range Stage 3 Intake manifold ﬂap Stage 2 When the engine is switched off, both ﬂaps are open. If the engine is idling, the two vacuum units are evacuated by the appropriate intake manifold changeover solenoid SSP217_032 valves.
Page 29 Effect of variable intake manifold on torque 1500 3000 4500 6000 7500 3360 5200 Speed SSP217_035 Lower full throttle (stage 1) Middle full throttle (stage 2) Upper full throttle (stage 3) Since the maximum torque across the speed The illustration explains the correlation range depends primarily on the length and between the length/cross section of the cross section of the intake manifold, the new...
Page 30 If a vacuum exists in the intake manifold, the reservoirs are evacuated via a non-return valve. SSP217_051 Fitting location of vacuum reservoir, Audi A8 Fitting location of vacuum reservoir, Audi A6...
Page 31 Secondary air inlet Vacuum unit, valve N112 stage 3 From vacuum reservoir SSP217_052 Non-return valve Intake manifold changeover solenoid valve N261, stage 2 From vacuum reservoir Intake manifold changeover solenoid valve N156, stage 2 Vacuum unit, stage 2...
Page 32: Secondary Air System
Engine - Motronic Subsystems Secondary air system J220 N112 G108 Energised Not energised V101 J299 SSP217_042 Owing to the high mixture enrichment during Air injection downstream of the outlet valves the cold-start and warm-up phase, an causes oxygen enrichment of the exhaust increased proportion of unburnt hydrocar- gases.
Page 33 Secondary air inlet valve N112 SSP217_001 Combination valve Cylinder bank 2 Connection for fresh air from secondary air pump V101 Combination valve Cylinder bank 1 Vacuum from engine Control line (vacuum or atmospheric pressure from secondary air inlet valve N112) Fresh air from secondary air pump V101...
Page 34 Engine - Motronic Subsystems Secondary air inlet valve N112 The secondary air inlet valve is an electro- To vacuum reservoir pneumatic valve. It is activated by the Motro- nic control unit and controls the combination valve. It releases the vacuum stored in the reservoir to open the combination valve.
Page 35 ﬁlter housing by the secondary air pump and released by the combination valve. The secondary air pump in the Audi A8 has its own air ﬁlter. The pump is integrated in the air ﬁlter housing where it draws in unﬁltered air.
Page 36: Engine Management
(with manual gearbox only) in dash panel insert Additional signals J218 – Air conditioner requirement signal – Air conditioner compressor, bidirectional – Crash signal – CCS switch * Air conditioner/Climatronic * No CAN businterface operating and display unit with Audi A6...
Page 37 Active components Fuel pump relay J17 and fuel pump G6 Injectors N30, N31, N32, N33 (bank 1) Injectors N83, N84, N85, N86 (bank 2) Ignition coil N (1st cyl.), N128 (2nd cyl.), N158 (3rd cyl.), N163 (4th cyl.) Ignition coil N164 (5th cyl.), N189 (6th cyl.), N190 (7th cyl.), N191 (8th cyl.) Activated charcoal ﬁlter system solenoid valve N80 Secondary air pump relay J299 and...
Page 38: Function Diagram
Lambda probe 2 Lambda probe heating 2 G163 Hall sender 2 G185 Accelerator position sender 2 S204 Fitting location in Audi A6: plenum chamber G186 Throttle valve drive next to battery (electric throttle operation) Fitting location in Audi A8: top right G187...
Page 39 S204 S117 S130 S116 J299 N156 N261 N112 N205 N208 N145 N144 V101 J220 N128 N158 N163 N164 N189 N190 N191 λ λ G108 G185 G163 G188 G187 G186 SSP217_044...
Page 40: Quick-Start Functions
Engine Management Quick-start functions Camshaft position sensor G40 and G163 As with the V6-5V engines, the new V8-5V engines also have two sensors for determining the position of the camshaft (G40 and G163). The sender system with “quick-start rotor ring“ already used in the 4- cylinder 5-valve engines is implemented.
Page 41: Engine Run-Down Sensor
The software reference mark is the point from which the control unit commences its calculations to determine the ignition point. It is about one tooth after the hardware reference mark, which is approximately 66˚ - 67˚ cr./shaft before ignition TDC of the 1st cylinder. Signal trace of engine speed sender G28, and Automatic mode Hall sender G40 and G163...
Page 42: Electronic Throttle Function
The ME 7.1 engine management system has to a large extent been described in SSP 198. The new functions and features of the system used in the V8-5V engine are dealt with below. Electronic throttle function Apart the following features, the electronic...
Page 43 Accelerator pedal module (Audi A6) No separate switch is used to provide kick- If the driver activates the kickdown, the full- down information. In the case of automatic- throttle voltage of the accelerator pedal gearbox vehicles, the accelerator pedal stop position senders is exceeded.
Page 44: Can Bus Interfaces
Engine Management CAN bus interfaces Gearbox control unit ESP control unit Adaptation release ASR request Idle charge compensation ASR intervention torque Switch off compressor (TARGET) Idling speed, target speed Brake pedal status Engine torque (TARGET) ESP intervention Emergency running program- Road speed mes (info via self-diagnosis) MSR request...
Page 45 In the Audi A8, data between the engine control unit and the other control units is, with the exception of a few interfaces, exchanged via the CAN system. Detailed information concerning the CAN data bus can be found in The system overview shows the information SSP 186.
Page 46: Additional Signals/ Interfaces
Engine Management Additional signals/ interfaces In the Audi A8, the following interfaces also In the A6, there will be no CAN data exchange exist for data exchange via CAN bus: with the dash panel insert when production of the model begins. For this reason, the A6...
Page 47 Crash signal Signal traces for crash signal using oscilloscope Automatic mode function of VAS 5051 5 V/Div. 0,1 s/Div. Standard signal Crash triggering SSP217_058 In the event of a crash where the belt In the event of a crash, the signal ratio is tensioners/airbags are triggered, the engine inverted for a deﬁned period of time.
Page 48 Self-diagnosis The crash signal is checked with respect to The fuel shut-off system will not be the plausibility of the crash signal and incorporated in the Audi A6 and A8 voltage. until model year 2000. Effect of fault If the “crash shut-off“ fault is stored in the...
Page 49: Service
Service A number of new special tools are required by the Service department for repairing the V8-5V engine. Thrust pad for crankshaft oil seal Order No.T40007 SSP213_007 Tensioning roller spanner Order No.T40009 SSP213_008 Camshaft retainer Order No.T40005 SSP213_009...
Page 50 Notes...
Page 51 Dear Reader, This self-study programme has allowed you to familiarise yourself with the new technical features of the V8-5V engine. Our aim is to make the content of the self-study programme material as interesting as possible. This is why we want to give you the opportunity to tell us your opinions and suggestions for future self-study programmes.

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V5 V8-5v

Audi V8 Service

Introduction

Engine - Mechanics

Engine - Motronic Subsystems

Engine Management

Service

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