Tài Liệu Động Cơ Audi 2.0l TFSI Engines EA888 Series

Learning objectives of this self study programme: This self-study programmme describes the design and function of the 2.0l 4-cylinder TFSI engine from the EA888 Gen.3 MLBevo engine serie

Service Training

Self Study Programme 645

For internal use only

Learning objectives of this self study programme:

This self-study programmme describes the design and function of

the 2.0l 4-cylinder TFSI engine from the EA888 Gen.3 MLBevo

engine series with power outputs of 140 kW and 185 kW

After you have completed this self study programme you will be

able to answer the following questions:

The 4-cylinder TFSI engine by Audi represents the next

evolution-ary step forward, the basis being the third-generation engine The

new engine is available with a displacement of 2 litres and in

2 performance classes, one of which supersedes the previous 1.8l

Gen.3 engine of performance class 1 (125 kW to 147 kW)

The aim of Audi’s designers was to reduce both CO2 and particulate

emissions in line with statutory requirements The 2.0l Gen.3 BC

engine shows that even fuel economy can be improved while

increasing engine displacement The abbreviation "BC" stands for

B cycle, a Miller combustion cycle which has now been refined by

Audi

The engine modifications for both performance classes are cal with respect to the engine mechanicals, where a number of friction-reducing measures have been implemented There are differences as regards charge cycles and the combustion process The performance class 1 engine operates on the Miller cycle, a patent dating from the year 1947 It was premiered in May 2015

identi-at the Vienna Motor Symposium as the most efficient petrol engine

in its class

More than 10 years earlier, Audi put into production the first turbocharged, direct injection TFSI engine and, thus, with the aid

of downsizing and downspeeding, set a milestone for

"Vorsprung durch Technik".

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This SSP contains a QR code which you can use to access additional interactive content (refer to "Information on QR codes" on page 30)

• What are the differences in terms of the engine mechanicals compared with the third-generation engines?

• What are the new features of the lubrication, charging, fuel and injection systems?

• How does the performance class 1 engine differ from the performance class 2 engine?

• How does the Miller cycle work?

Introduction

Objective _ 4Development of the engine series _ 5

Presentation

Specifications 6Third-generation MLBevo 2.0l TFSI engine _ 8Third-generation MLBevo BC (Audi ultra) 2.0l TFSI engine 10

Engine mechanicals

Crankshaft drive 12Engine block 14Engine oil 0W-20 _15Cylinder head _16Chain drive 18

Engine management

Air mass meter _20Combustion process _20Miller cycle 21New TFSI combustion process by Audi (B cycle) 22

Reference

Note

The self study programme teaches a basic understanding of the design and mode of operation of new models,

new automotive components or new technologies

It is not a repair manual! Figures are given for explanatory purposes only and refer to the data valid at the

time of preparation of the SSP This content is not updated.

For further information about maintenance and repair work, always refer to the current technical literature

In the glossary at the end of this self study programme you will find an explanation of all terms written in

italics and indicated by an arrow ↗.

Contents

Objective

By adopting a process known as rightsizing, Audi has, after

down-sizing, taken a further, decisive step forward Innovative engine

technologies are selectively combined and configured in such a way

that displacement, power output, torque, fuel consumption and

operating conditions are optimally balanced

The new engines have all the fuel economy advantages of a

down-sized unit in partial-load operation At higher engine loads, they

draw on the benefits of the high-displacement engine This

pro-vides an optimal combination of efficiency and performance across

the entire rev band

For the first time, these engines are being used in the latest generation of the Audi A4 (type 8W) Audi also plans to employ these units in a number of Group vehicles in both longitudinal and transverse configurations

The descriptions in this self study programme refer to the dinal engines in the Audi A4 (type 8W) at the start of production

• Audi's first EA888 TFSI engine

• 1.8l and 2.0l variants

• Demand-controlled fuel system

• Camshaft drive via timing chain

• Variable valve timing on the exhaust side

Self Study Programme 384

"The Audi 1.8l 4V TFSI engine with timing chain"

• On-demand oil delivery

• Audi valvelift system (AVS) on the exhaust side

• Secondary air system for SULEV engines

Self Study Programme 436

"Modifications to the chain-driven 4-cylinder TFSI engine"

• Exhaust manifold integrated in the cylinder head (IAGK)

• Innovative thermal management (ITM) system with actuator for engine temperature control

• Boost is provided by a turbocharger with electrical wastegate actuator

• Dual injection system (MPI ↗ and FSI ↗)

Self Study Programme 606

"Audi 1.8l and 2.0l series EA888 TFSI engines

(third generation)"

• New TFSI combustion process

• Audi valvelift system (AVS) on the intake side

• Supersedes the 1.8l variant

The EA113 or EA888 engine series has for many years been used in

a number of Audi models and provides a broad basis for petrol

engine configurations Development of this engine series was

principally focused on improving fuel economy and reducing CO2

↗ Refer to "Glossary" on page 28

< Back Forward > Ξ Contents

Power output in kW in efficiency mode 1)

Torque in Nm in efficiency mode 1)

In efficiency mode: 250 at 1200 – 53001)

idle charge compensationExhaust gas treatment Close-coupled ceramic calatyst, oxygen sensors before and after catalytic converter

idle charge compensationExhaust gas treatment Close-coupled ceramic calatyst, oxygen sensors before and after catalytic converter

1) Audi A4 saloon with front wheel drive and S tronic

2) Audi A4 Avant with quattro drive and S tronic

↗ Refer to "Glossary" on page 28

< Back Forward > Ξ Contents

Third-generation MLBevo 2.0l TFSI engine

(performance class 2)

Pistons

• The piston has the same geometry as in the 165 kW basic engine

• The piston is made from the same material as in the Audi S3 (type 8V)

• 3-piece oil control ring

Below you will find a summary of the key differences compared

with the third-generation 2.0l TFSI engine If the car is equipped

with a start-stop system, a Version 2.0 system is generally used

For more information about the versions of start-stop systems,

please refer to Self Study Programme 630 "Audi TT (type FV)"

The basis for the third-generation MLBevo 2.0l TFSI engine is the

165 kW 2.0l TFSI engine from the Audi A4 (type 8K) (engine code CNCB)

Engine management

• Simos 18.4 system

• Throttle valve with reduced air leakage

• The throttle valve and the high-pressure fuel pump are supplied by Bosch

• Engine control unit interface to the FlexRay bus system

ACF system

• Increased air flow

• Noise reduction measures

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Oil supply

• Modified to create space for the use of electromechanical steering (ESP) and the planned roll stabilisation system.

• A non-return valve in the oil filter module allows maximum oil pressure to

be built up more quickly at all lubrication points, especially when the engine is cold There is no non-return valve in the engine block or in the cylinder head.

• Increasing the oil volume between minimum and maximum oil levels ensures that a sufficient volume of oil is available at the intake end of the oil pump whenever the driver adopts an especially dynamic driving style.

Cylinder head

• An alternative material is used to allow for higher power output and the resultant higher levels of thermal stress

• The coolant jacket is now thicker

• The valvegear has been modified, e.g by using sodium-filled exhaust valves, to allow for higher power output and the resultant higher levels of thermal stress

• The exhaust turbocharger has been uprated for temperature stability up to

950 °C

Engine block

• The ventilation system has been rerouted across the balancer shafts.

• The modifications to the positive crankcase ventilation system necessitate directional installation of the piston cooling jets (refer to workshop manual)

Modifications to ULEV 125 (USA)

• No multi-point injection (MPI)

• Diagnosable PCV system ventilation hose (mandatory)

Third-generation MLBevo BC (Audi ultra) 2.0l TFSI engine

(performance class 1)

Engine management

• Bosch MED 17.1.10 system

• New combustion process (BC = B cycle)

• Use of an air mass meter for the new combustion

process

Below you will find a summary of the key differences compared

with the third-generation MLBevo 2.0l TFSI engine with a power

output of 185 kW

Chain drive

• Longer guides

• Non-circular sprocket for timing drive

• Chain tensioner with lower tensioning force

• Faster oil pump gear ratios,

sprocket with 22 teeth (previously 24 teeth)

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Fuel system

• Pressure increase to 250 bar

• Adaptation of the components in the high-pressure

system

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Cylinder head

• Audi valvelift system (AVS) on the intake side

• Redesigned intake ports

• Masked combustion chambers

• Valve guide housings for better heat dissipation

• Double-lip exhaust valve stem seals

Crankshaft

• Reduced main bearing diameter

Pistons

• Friction reduction measures

• Pistons with modified crowns

Other modifications:

• Vacuum pump by Bosch

• Smaller exhaust turbocharger, adapted thermodynamics

• New engine oil 0W-20 (compliant with VW 50800 and VW 50900)

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Crankshaft drive

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When work began on the development of the crank train, the focus

was on reducing friction and weight

• Reduced bearing diameter

in performance class 1 engine

However, there are several differences between the performance class 1 and 2 engines These are explained below

Overview

↗ Refer to "Glossary" on page 28

Engine mechanicals

These components for the performance class 2 engine have, to the

greatest possible extent, been adopted from the precedessor

engine Only the piston rings have been modified A 3-piece oil

control ring is now used (refer to "3-piece oil control ring" on

page 27)

Further modifications were made to the performance class 1

engine due to the higher compression levels and the new TFSI

combustion process

The combustion chambers have larger crumple zones (masking)

necessitating the use of smaller intake valves

Enlarged epsilon zone

Adapted valve recesses

Smaller intake valves

Masking

The main bearings of the performance class 2 engine have the

same diameter as in the third-generation engine The main

bear-ings of the performance class 1 engine are of the same size as in

Equi-sized exhaust valves

Flow recess

the previous 1.8l TFSI engine This has made it possible to achieve further weight savings Both crankshafts uniformly have 4 counter-weights

The enlarged crumped zones enhance the swirling action of the fuel/air mixture inside the cylinder Accordingly, use is made of shaped valve recesses in the piston crowns and an enlarged

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Positive crankcase ventilation

Due to the Audi valvelift system (AVS) being relocated to the intake

side of the performance class 1 engine, it was necessary to adapt

the positive crankcase ventilation system Instead of the previous

extraction points in the crank chambers of cylinders 3 and 4, the

blow-by gases ↗ are now extracted from the crank chambers in the

area of cylinders 1 and 2

The blow-by gases flow from here into the housing of a balancer

shaft

Engine block

Blow-by gas extraction points

in crank chambers 1 and 2

A slotted sleeve which allows through-flow of the blow-by gases is integrated in the balancer shaft housing

The rotation of the balancer shaft (centrifugal effect) ensures that

a large proportion of the oil is separated from the blow-by gases (coarse oil separator) and flows back into the oil pan The onward flow path of the blow-by gases to the fine oil separator module on the cylinder head is otherwise identical to that of the third-genera-tion 2.0l TFSI engine

Slotted sleeve

Balancer shaft

Blow-by gases in the engine block

Flow of blow-by gases

to the fine oil separator module

Reference

For more information about the fine oil separator module and how it works, please refer to Self Study Programme 606

"Third-generation Audi 1.8 and 2.0l TFSI EA888 series engines"

Blow-by gas intake points in the crank chamber of cylinders 1 and 2

↗ Refer to "Glossary" on page 28

Piston cooling jets

Given that the performance class 1 engine uses a modified positive

crankcase ventilation system where the blow-by flow gases flow

around one of the balancer shafts, it was also necessary to effect

changes in the manufacturing of the engine block As a result, the

piston cooling jets are now no longer abutting the crank chamber

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Reference

For further information about installation of the piston jets, please refer to the workshop manual

Engine oil 0W-20

To further reduce the friction and thereby improve fuel economy,

the performance class 1 engine uses an engine oil with the 0W-20

specification in compliance with the VW 50800 and VW 50900

standards

The new engine oil has the following properties:

• It allows faster pressure build-up because it has a low viscosity,

enabling it to reach the lubrication points more quickly In

addition, it is more cost-effective for drivers with a short

dis-tance profile because less friction loss occurs in the engine

(lower oil resistance)

• A chemical marker has been added to the new oil (green

colora-tion) so it can be identified more easily in a laboratory

• The oil is not downwardly compatible, i.e. it is only suitable for use in approved engines

• Oil pressure builds up slightly more slowly due to the low viscosity of the oil This is why the oil pump runs slightly more slowly in the third-generation MLBevo 2.0l TFSI engine of performance class 1 In addition, a new non-return valve is integrated in the oil filter housing

Previously, a contact edge was required for this purpose For this reason, care must be taken to ensure that the piston cooling jets are exactly aligned during installation in the new engine If this is not the case, the reliable functioning of the piston cooling system cannot be guaranteed

Contact edge for the piston cooling jet on the crank chamber

Piston cooling jet requiring directional installation

Cylinder head

Whereas the cylinder head of the performance class 2 engine is to

a large extent a carry-over from the third-generation 2.0l TFSI

engine, a number of modifications have been made to the cylinder

head of the performance class 1 engine

The cylinder head of the performance class 1 engine has the

following modifications:

• The Audi valvelift system (AVS) has been moved to the intake

side

• The cylinder head cover has been adapted to accommodate the

new installation position of the Audi valvelift system (AVS)

• The compression ratio has been increased from 9.6:1 to 11.7:1

by reducing the volume of the compression chamber

• Modified valve masking

• Lowering of combustion chamber ceiling by 9 mm

• Modified piston shape

Masking

This was necessary to implement the new TFSI combustion process However, this has also improved running refinement and reduced knock tendency

• FSI injectors are positioned closer to the combustion chambers

• The intake ports have been redesigned, i.e made straighter, to optimise charging motion

• The positions of the spark plug and high-pressure injector as well as the shape of the piston have been adapted to the new combustion chamber design

• Valve guide housings for better heat dissipation

• Double-lip exhaust valve stem seals