The V8-5V Engine Construction Features and Functions Self-Study Program Course Number 921903 The V8-5V Engine AUDI has been producing advanced Steps to enhance the value of the Audi AS ' r S-cylinder engines since 19SS. Their have included the redesign of the capacity has increased from 3.6 L to 4.2 L. VS engine. The VS engine in combination with The new VS-5V engines are now also Aluminum Space Frame technology was available for the Audi A6 model range. the technical basis for Audi's breakthrough into the luxury class. Audi of America, Inc. Service Training Printed in U.S.A. Printed 9/99 Course Number 921903 All rights reserved. All information contained in this manual is based on the latest product information available at the time of printing. The right is reserved to make changes at any time without notice. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publisher. This includes text, figures and tables. Always check Technical Bul letins and the Audi Worldwide Repair Information System for information that may supersede any information included in this booklet. 1 Contents The V8-5V Engine ....... ................ ............................................. 1 Engine - Mechanics .......................................... ...................... 4 The V8-5V Engine, The Tec hnical Data, Crankcase, Engine Mounting, Engine Lubrication, Cooling Circuit, Cylinder Head, Exhaust Manifold Engine - Variable Intake Manifold ....................................... 29 Intake Module, Operating Stages, Effect of Variable Inta ke Manifold on Torque, Vacuum Reservoirs Engine - Secondary Air System .......................................... 34 Secondary Air System Overview, Component Function Engine Management ................................................... .......... 38 Motronic ME 7.1 System Overview, Functional Diagram, Quick-Start Functions, Electronic Throttle Function, The CAN Data Bus, CAN Bus Interfaces, Additional Signals/Interfaces Service ........................ ............................................................ 57 Special Tools New! Teletest ................................................................................... 59 Audi V8-5V Engine Teletest Important/Note! This Self-Study Program provides you with information concerning the engine's construction features and functions. The Self-Study Program is not a Repair Manual! W hen ca rrying out maintenance and repa ir work, it is essential to use the latest technical literature. ' • 3 Engine - Mechanics l! Engine - Mechanics f 4.2L V8-5V Engine The V8-5V Engine The Technical Data lbs-ft Nm kW hp 369 500 250 335 Major modifications were made to the VS New Features A6 A8 f 332 450 225 302 engines during the course of further 4.2 L 4.2 L • Five-valve cylinder head with f development. 295 400 200 268 ro ller rockers Engine code ART AKB Emphasis was placed on the following 258 350 175 235 • Camshaft adjustment development objectives: I 221 300 150 201 Design VS engine with 90° V angle • Three-stage variable intake manifold 4l ... • compliance with future exhaust-emission :I :I ...CT 184 250 125 168 Q. ...:I regulations • Engine management system, Capacity 255 cu in 255 cu in {: 0 148 200 100 134 Bosch ME 7.1 3) 3) • reduction of fuel consumption (4172 cm (4172 cm i 111 150 75 101 • Electro-hydraulic engine mounting I I I • increase in torque and power Power output 300 hp 310 hp i 74 100 50 67 • improvement of comfort and Modifications (220 kW) (22S kW) 37 50 25 34 convenience at at • to crankcase and crankgear 6200 rpm 6200 rpm 0 0 • reduction of engine w eight 0 1000 2000 3000 4000 5000 6000 7000 • to oil circuit Speed (RPM) SSP 217/005 • increased use of shared components for I Torque 295 lbs-ft 302 lbs-ft • to cooling circuit the AUDI engine series. t (400 Nm) at (410 Nm) at 3000 rpm 3000 rpm The specified power data is The following new features and only possible if 91 AKI fuel modifications were added to t he Bore 3.32 in 3.32 in is used. A reduction in power VS 4-valve engine design to (S4.5 mm) (S4.5 mm) \._j output must be expected if develop the new I lower grade fuel is used. VS-5V engine. Stroke 3.66 in 3.66 in • (93.0 mm) (93.0 mm) Compression ratio 1O.S :1 1 O.S:1 Weight 441 lbs 441 lbs (200 kg) (200 kg) Engine Motronic Motronic management ME 7.1 ME 7.1 Fuel 91 AKI 91 AKI Firing SSP 213/073 sequence 1 -5-4-S-6-3-7-2 4 5 - Engine - Mechanics Engine - Mechanics Crankcase The crankcase has been adapted to the modifications made to the oil supply system and cooling circuit. ' SSP 21 7/055 SSP 217/054 Cold-cracked connecting rods have Recesses are designed into the tops of been used for the 3.7 L engine since pistons to provide clearance for valves. 1995 and are now also being used for Pistons are not interchangeable between the 4.2 L engine. cylinder banks. SSP 217/002 6 7 - Engine - Mechanics Engine - Mechanics Engine Mounting Wide, milled ventilation recesses above the thrust bearings reduce pumping losses. To enhance driving comfort, hydraulic engine mounts with electrical activation are Bolts are also inserted at the sides of used for the eight-cylinder engines. the two front crankshaft bearing caps to improve running smoothness. The mounts are activated by the engine control module according to engine speed. Two hydraulically damped engine mounts reduce the transfer of engine vibrations to SSP 217/007 the body across the entire rpm range . Electrical Connection The locking mandrel (V.A.G. 3242) used Damping is adjusted to compensate for two SSP 217/039 for the V6 engines is also used for locking operating states, idling and driving. the crankshaft on the V8-5V engines. It is applied to the crank web of the fourth cylinder and is used for basic engine - Hydraulic Fluid Rubber adjustment and also as a counterhold for - Plastic Body Membrane loosening and tightening the central bolt of the crankshaft. - Atmosphere/Air t Housing The fifth cylinder must be set Airway to the to ignition TDC. Atmosphere Lower SSP 217/009 • Chamber Marking ' Rubber Diaphragm The central bolt does not have to be Solenoid Va lve for unscrewed for the vibration damper to Electro-Hydraul ic Engine Mount be removed. Restrictive Flu id Channel The marking indicates the ignition TDC of SSP 183/03 the fifth cylinder. Each engine mount consists of: • a rubber and metal housing • a rubber membrane • a plastic body with restrictive • a rubber diaphragm fluid channel • a solenoid valve • an upper and a lower chamber Central Bolt SSP 217/050 filled with hydraulic fluid 8 9 -- Engine - Mechanics Engine - Mechanics Engine Mount Operation At driving speeds (above 1100 rpm) the engine mount is hard. t At idle speed (below 1100 rpm) the engine mount is soft. At driving speeds, a combination of engine­ Upper Chamber Rubber induced high-frequency vibrations with The hydraulic fluid in the upper chamber of M embra ne small vibrational distances and road-induced each engine mount is pressurized by the low-frequency vibrations w ith larger movement created by engine vibrations. At vibrational distances overlap each other. Rubber M embrane idle speed, the high-frequency engine vibrational distances are small. At engine speeds above 1100 rpm, the engine mount solenoid valve is closed by Solenoid Valve These high-frequency vibrations do not the engine control module. This blocks the create enough pressure to push the plastic body airway to the atmosphere and hydraulic oil from the upper chamber creates a relatively hard cushion of air through the restrictive fluid channel to the under the rubber membrane that separates low er chamber. The airway in the plastic the hydraulic fluid from the air chamber. body is open to the atmosphere and the High-frequency vibrations continue to be rubber membrane that separates the Restrictive absorbed by the rubber membrane at the hydraulic f luid from the air creates a Fluid Channel air cushion. relatively soft cushion that absorbs the Airway Air Cushion high-frequency vibrations transmitted to the The low-frequency vibrations induced by Lower Chamber through the hydraulic fluid. Atmosphere t the roadway now create sufficient pressure Hydraulic Fluid in the hydraulic fluid to force it through the - Hydraulic Flu id Plastic Body restrictive fluid channel in the plastic body - - Plastic Body Atmosphere/Air that separates the upper and lower - chambers. As the hydraulic fluid enters the - Atmosphere/Air Housing SSP 183/98 lower chamber, the rubber diaphragm that - Housing SSP 183/99 lines the lower chamber distorts, reducing the effect of the low-frequency vibrations. Frequency: This term is used to The low-frequency engine define vibration characteristics . vibrations with large vibrational Vibration frequency is measured distances are actually induced by as the number of vibration cycles vehicle travel over the roadway. 0 per second and is expressed in If the hydraulic engine mounts hertz (Hz). are defective, these vibrations are not damped properly and overall engine vibration increases 10 11 Engine - Mechanics Engine - Mechanics Engine Lubrication Slight modifications have been made to the been used since the introduction of the oil circuit in the cyl inder heads. new model. Cylinder bank 1 shows the A duocentric oil pump driven by the • There are five oil bores per triple roller The oil circu it for cylinder bank 2 shown in modified oil circuit. crankshaft via a chain replaces the rocker. Three oil bores each supply one the illustration is the oil circuit that ha s previously used external gear oil pump. hydraulic tappet. Two oi l bores supply the Cylinder Ban k 1 Cylinder Ba nk 2 oil-spray bores integrated in the rol ler The duocentric oil pump extends deep into rocker to lubricate the ro llers.