Self-Study Program 920213

The Second Generation 3.0L V6 TDI Engine

Audi of America, LLC
Service Training
Printed in U.S.A.
Printed 9/2012
Course Number 920213

©2012 Audi of America, LLC

All rights reserved. Information contained in this manual is
based on the latest information available at the time of printing
and is subject to the copyright and other intellectual property
rights of Audi of America, LLC., its affiliated companies and its
licensors. All rights are reserved to make changes at any time
without notice. No part of this document may be reproduced,
stored in a retrieval system, or transmitted in any form or by
any means, electronic, mechanical, photocopying, recording or
otherwise, nor may these materials be modified or reposted to
other sites without the prior expressed written permission of
the publisher.

All requests for permission to copy and redistribute
information should be referred to Audi of America, LLC.

Always check Technical Bulletins and the latest electronic
service repair literature for information that may supersede any
information included in this booklet.

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Technical Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Engine Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Cylinder Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Crankshaft Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Chain Drive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Cylinder Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Oil Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Oil Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Engine Oil Pump with Integral Vacuum Pump . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Engine Oil Cooler with Thermostat Controlled Bypass Port. . . . . . . . . . . . . . 11

Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Coolant Circuit and Thermal Management System . . . . . . . . . . . . . . . . . . . . . 13
Cylinder Head Cooling Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Cylinder Block Cooling Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Exhaust Gas Recirculation . . . . . . . . . . . . . . . . . . . . . . . . . .16
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Active EGR Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Intake Air Ducting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Turbocharging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Charge Air Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Common Rail Injection System . . . . . . . . . . . . . . . . . . . . .21
Chain-Driven Injection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Fuel Delivery System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Engine Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Special Tools and Workshop Equipment . . . . . . . . . . . . .26
Knowledge Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . .29

i

The Self-Study Program provides introductory information regarding the design
and function of new models, automotive components, or technologies.
The Self-Study Program is not a Repair Manual!
All values given are intended as a guideline only.
For maintenance and repair work, always refer to current technical literature.

ii

Reference

Note

!

Introduction
The success story for V6 TDI engines at Audi
began in 1997 with the introduction of the
world’s first four-valve 2.5 liter V6 TDI with a
distributor injection pump fuel system.
In late 2003, this engine was followed by a 3.0
liter V6 TDI with common rail fuel injection. A
power reduced 2.7 liter version was introduced
in 2004 but was not offered in the U.S. market.

The second generation 3.0L V6 TDI engine
features state-of-the-art diesel technology, such
as a common rail fuel system with piezo fuel
injectors, systematic thermal management, and
extensive friction reducing improvements. This
ensures that lower emissions and higher fuel
economy are achieved.

V6 TDI engines have evolved with much success
in various Audi and VW Group models.

479_001

1

Technical Features

Bosch CRS 3.3 common
rail injection system

479_008

Intake manifold with
a single swirl flap

479_012

Chain drive

479_003

2

Turbocharger module

479_005

Exhaust gas
recirculation

479_002

479_004

Thermal management system

479_010
3

Specifications

268.2 hp (200 kW)

442.5 lb ft (600 Nm)

234.6 hp (175 kW)

405.6 lb ft (550 Nm)

201.1 hp (150 kW)

368.7 lb ft (500 Nm)

167.6 hp (125 kW)

331.9 lb ft (450 Nm)

134.1 hp (100 kW)

295.0 lb ft (400 Nm)

Power in hp (kW)
Torque in lb ft (Nm)

hp (kW)

lb ft (Nm)

67.05 hp (50 kW)

221.2 lb ft (300 Nm)

0

1000

2000

3000

4000

5000

6000
479_019

4

Engine Code (model dependent)

Q7: CNRB, Q5: CPHA, A8: CPNA

Engine type

Six-cylinder 90° V-engine

Displacement

181.0 cu in (2967 cm3)

Stroke

3.59 in (91.4 mm)

Bore

3.26 in (83 mm)

Cylinder spacing

3.54 (90 mm)

Number of valves per cylinder

4

Firing order

1-4-3-6-2-5

Compression ratio

16.8 : 1

Power output

246.7 hp (184 kW) @ 4000 rpm

Torque

405.6 lb ft (550 Nm) @ 1250–3000 rpm

Fuel

Diesel to EN 590

Engine management

Bosch CRS 3.3

Emissions standard

ULEV Tier II Bin5

Engine Design
Cylinder Block
The cylinder block is made from vermicular
graphite cast iron (CJV-450). This material
provides high strength and load capacity. The
proven bearing frame design principle from the
previous generation V6 TDI engine has been
adopted for the crankshaft bearings of this
engine.

The weight of the cylinder block has been
reduced by 17.6 lb (8.0 kg) when compared
to the first generation V6 TDI engine. This
was accomplished partly through systematic
reductions in wall thickness.

Cylinder block

Balance shaft

Dividing plane at
center of crankshaft
Crankshaft

Oil pan
upper section

479_013

Bearing frame

To ensure a perfectly round cylinder shape, the
cylinder block is plate honed during the final
machining processes. A special plate is mounted
on the cylinder block to simulate the effect of an
installed cylinder head.

At the final stage of cylinder bore machining,
the UV photon exposure process is applied. This
ensures that a smooth cylinder bore surface is
obtained without necessitating mechanical work
(wear-in) by the piston.

A round bore ensures a substantial reduction
in piston ring pre-stress which results in lower
blow-by gases and less mechanical friction.
5

Crankshaft Assembly
The forged 42 CrMo54 crankshaft has a split pin
design to achieve identical firing intervals.

The forged connecting rods are diagonally split
and cracked at the big end.

Due to the strong shear forces to which the
crankshaft is subjected, both the main bearing
journals and connecting rod journals are
induction hardened.

Approximately 2683.1 psi (185 bar) are generated
during the combustion process. For optimal
cooling of the piston ring assembly and recess
rim, the aluminum pistons have an annular salt
core cooling gallery and are sprayed from below
by oil jets mounted on the cylinder block.

Weight to the crankshaft assembly has
been reduced by eliminating the center
counterweights and machining relief bores in
the main journals.

Annular oil
cooling gallery

Trapezoidal
connecting rod

Split pin connecting
rod bearing journal

Oil supply port of the
connecting rod bearings

Transverse bore
in the crankshaft

Connecting
rod bearing

Connecting
rod cap

479_016_018

6

Chain Drive System
The second generation V6 TDI engine has a
new chain drive layout compared to the first
generation V6 TDI.
The new chain layout reduces the number of
chains and chain tensioners from four to two
and eliminates the need for idler sprockets.
A relatively long roller chain (206 links) is used
to drive the intake camshafts and balance shaft.
To counteract chain elongation, the chain pins
have a wear-resistant coating.

The auxiliary drive chain is also a roller-type. It
drives the high-pressure fuel injection pump
in the rear inner Vee of the engine, and the
combined oil pump/vacuum pump.

High-pressure
pump CP4.2

Balance shaft
Timing gear for camshafts
and balance shafts
Timing drive
chain tensioner

Auxiliary drive
chain tensioner

Vacuum pump

Crankshaft

479_003
Two-stage variable
oil pump

Auxiliary drive

7

Cylinder Head
The proven first generation V6 TDI four-valve
cylinder head design has been adapted for the
second generation engine.
This new engine features swirl ports and
charging ports in the intake, both of which have
been redesigned to enhance swirl and throughflow, while the exhaust side has two exhaust
ports merging into a Y-branch pipe.
The cylinder head cooling concept has been
revised to reduce component temperatures
around the combustion chamber despite
increased engine power output.
The exhaust valves have been reduced in size
and moved further apart. This reduces the
area needed to be cooled. The cylinder head is
designed for directional coolant flow with high
flow rates. This ensures that optimal cooling
is provided between the valves and the fuel
injector bore, which are in close proximity to the
combustion chamber.

The Hydro-formed hollow camshafts are
mounted on the cylinder heads on split twin
bearing pedestals rather than a ladder frame.
The camshafts have been repositioned inward
(or closer to each other) allowing them to be
designed without additional clearances to
access the head bolts.
To minimize friction in the valve train, the
diameter of the camshaft bearings has been
reduced to 0.9 in (24.0 mm) from 1.25 in
(32.0 mm).
The crankcase ventilation system (both coarse
and fine oil separators) has been moved from the
Vee of the engine into the cylinder head covers.
Both crankcase vents lead to the pressure
control valve and from there to the intake side of
the turbocharger.

Action spring

Swirls
Sealing cover
with swirl port

Constant-pressure
valve

Oil return
line

Fine oil
separator
Oil separator
module

Blow-by
gas inlet

Composite hollow
camshafts

Camshaft bearing
pedestals
Pretensioned gears
to drive the
exhaust camshafts
Glow plug