SSP 920273

The Audi 2.5l TFSI Engine EA855 EVO Series
Self Study Program 920273
Audi of America, LLC
Service Training
Created in the U.S.A.
Created 07/2017
Course Number 920273
©2017 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
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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.
Revision:7/2017
ii
Contents
Introduction ....................................................................................... 1
Engine description and special features ................................................................................................................... 2
Specifications .............................................................................................................................................................. 3
Engine mechanicals............................................................................. 4
Cylinder block .............................................................................................................................................................. 4
Timing case (cover for timing chains) ....................................................................................................................... 5
Oil pan top and bottom sections ............................................................................................................................... 5
Crankshaft drive .......................................................................................................................................................... 6
Pistons and connecting rods ..................................................................................................................................... 7
Cylinder head .............................................................................................................................................................. 8
Audi valvelift system (AVS) ......................................................................................................................................12
Timing assembly .......................................................................................................................................................16
Accessory belt drive ..................................................................................................................................................18
Positive crankcase ventilation .................................................................................................................................20
Oil supply........................................................................................... 28
Overview ....................................................................................................................................................................28
Oil pump ....................................................................................................................................................................30
Oil filter housing / oil cooler ....................................................................................................................................32
Oil flow .......................................................................................................................................................................33
Cooling system.................................................................................. 34
Overview ....................................................................................................................................................................34
Innovative Thermal Management (ITM) .................................................................................................................36
Sensors in the coolant circulation system ..............................................................................................................37
Actuators in the coolant circuit ...............................................................................................................................38
Air supply and turbocharging............................................................ 40
Overview ....................................................................................................................................................................40
Intake manifold ........................................................................................................................................................40
Turbocharging ...........................................................................................................................................................42
Exhaust system................................................................................. 44
Overview ....................................................................................................................................................................44
Catalytic converter module ......................................................................................................................................44
Switchable exhaust valves .......................................................................................................................................45
Fuel system....................................................................................... 46
Overview ....................................................................................................................................................................46
Fuel injectors .............................................................................................................................................................47
Intermediate Shaft Speed Sensor G265 ................................................................................................................47
Combustion process .................................................................................................................................................48
Operating modes ......................................................................................................................................................49
Engine management......................................................................... 50
System overview .......................................................................................................................................................50
Inspection and maintenance............................................................. 52
Service information and operations ........................................................................................................................52
Special tools and workshop equipment .................................................................................................................52
Appendix........................................................................................... 54
Glossary .....................................................................................................................................................................54
Self-Study programs ................................................................................................................................................55
Knowledge assessment..................................................................... 56
The eSelf-Study Program (eSSP) teaches a basic understanding of the design and mode of operation of new models, new
automotive components or new technologies.
Note
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.
For further information about maintenance and repair work, always refer to the current technical literature.
Reference
iii
iv
Introduction
Audi launched its first five-cylinder engine for the North
American market in 1977 with the Audi 5000. These engines
have been the staple of the Audi product range ever since
and have been used successfully in both production and
racing cars. They have achieved cult status, not least
because of their distinctive sound. Even today they offer an
emotional driving experience. The five-cylinder era continued
until 1998 when a new V6 TFSI engine was introduced.
However, the five-cylinder made a comeback with the introduction of the Audi TT RS. Since 2010, the 2.5 TFSI engine has
been voted “International Engine of the Year” in its class for
seven consecutive years by an international jury of motorists.
The new 2.5 liter R5 TFSI engine of the EA855 EVO series
replaces the previous 2.5 liter R5 TFSI engine and makes its
North American debut in the Audi TT RS. There are also plans
to use this engine in other models including the Audi RS3.
Learning objectives of this Self-Study Program:
This Self-Study Program describes the design and function of
the fourth-generation 2.5l R5 TFSI engine of the EA855 EVO
series in the Audi TT RS.
After completing this Self-Study Program you will be able to
answer the following questions:
›› What are the differences between the new engine and its
predecessor?
›› Which structural design measures are used to achieve lightweight design?
›› How do the oil supply and engine cooling systems work?
›› What are the special features of the air supply system?
›› How do the new injection process and the engine management system work?
1
Engine description and special features
›› 5-cylinder in-line gasoline engine.
The key differences to the previous model:
›› Aluminum cylinder block.
›› 4 valves per cylinder, double overhead camshafts
(DOHC).
›› Exhaust turbocharger with charge air cooling (maximum
charge pressure: 19.6 psi [1.35 bar]).
›› Twin path exhaust system with one close-coupled precatalytic converter, one broadband oxygen sensor (sixwire) upstream of the main catalytic converter, one
heated oxygen sensor (four-wire) just after the main
catalytic converter.
›› Variable valve lift adjustment with Audi valvelift system
(AVS) on the exhaust side.
›› Direct charge air cooling (air to air intercooler).
›› Fully electronic engine management system with EPC.
›› Dual system with fuel straight injection (3626 psi [250
bar]) and cylinder-selective multipoint injection.
›› Adaptive lambda control.
›› 57.32lb (26 kg) less weight.
›› Reduced friction.
›› The installed length of the engine has been reduced by
creating a more compact installation space in the area of
the rear chain drive and by switching to a single-track
accessory belt drive.
›› Increased engine power and torque.
›› Better fuel economy.
›› MPI / FSI injection system.
›› Thermal management (active coolant pump).
›› Intelligent thermal management.
Key factors contributing to this reduction in weight are the
aluminum cylinder block, a magnesium oil pan top section,
an aluminum hydraulic vibration damper, a lighter crankshaft and the extensive use of aluminum bolts.
›› Mapped ignition with single ignition coils.
›› Cylinder-selective adaptive knock control.
›› Intelligent thermal management.
661_003
2
Specifications
Torque-power curve of 2.5l R5 FSI engine
(Engine code DAZA)
472 (640)
429 (320)
	  Power output in hp (kW)
	  Torque in lb ft (Nm)
413 (560)
375 (280)
354 (480)
322 (240)
295 (400)
268 (200)
236 (320)
215 (160)
177 (240)
161 (120)
118 (160)
107 (80)
59 (80)
54 (40)
Engine speed [rpm]
661_004a
Features
Specifications
Engine code
DAZA
Type
5-cylinder inline engine
Displacement
151 cu in (2480 cc)
Stroke
3.65 in (92.8 mm)
Bore
3.25 in (82.5 mm)
Cylinder spacing
3.46 in (88.0 mm)
Number of valves per cylinder
4
Firing order
1-2-4-5-3
Compression ratio
10.0 : 1
Power output at rpm
400 hp (298 kW) at 5850 - 7000
Torque at rpm
354 lb ft (480 Nm) at 1700 - 5850
Fuel type
Premium unleaded
Turbocharging
Exhaust turbocharger with charge air cooling
(maximum boost pressure: 19.6 psi [1.35 bar])
Engine management
Bosch MED 17.01.62
Engine weight acc. to DIN GZ ↗
352.7 lb (160 kg)
Exhaust gas treatment
Close-coupled pre-catalytic converter, broadband oxygen sensor upstream of precatalytic converter, heated oxygen sensor downstream of pre-catalytic converter
Emission standard
LEV3 / Tier 3
3
Engine mechanicals
Cylinder block
The cylinder block is aluminum alloy (ALSi7Mg0.3).
The “deep skirt” design is manufactured in a "Rotacast"
process ↗.
The cylinder liners are manufactured in an APS (Atmospheric Plasma Spraying) process ↗. While cooling is provided by coolant jackets located between the cylinders.
To increase strength, the main bearing caps are laseretched and cross-bolted. In addition, the coolant passages and high pressure fuel pump mount are integrated
in the cylinder block.
Piston cooling jet
Main bearing cap
Timing chain cover
Oil Level Thermal Sensor
G266
Laser etched
4
Timing case (cover for timing chains)
››
››
››
››
21.1 oz (600 g) less weight.
More flexible attachment to cylinder head.
Reduced overall height.
Attachment for Intermediate Shaft Speed Sensor G265.
Inter-cylinder baffle cooling
Cylinder 1
Sealing flange on belt pulley side
Cylinder block
Roughened exterior surface
Cross bolt
APS cylinder liner coating
Oil pan top section
mounting bolts
Oil pan top and bottom sections
Oil pan top section
The oil pan top section is made from a magnesium alloy
(MgALRE-2) which reduces its weight by 4.1 lb (1.9 kg)
when compared to the previous engine. The oil pan top
section is additionally reinforced by a threaded connection
on the bearing cap.
The weight of the oil pan bottom section has also been
reduced by 2.2 lb (1.0 kg) when compared to the previous
engine by switching from sheet steel to sheet aluminum.
The overall oil system has been optimized for use in racing
without the need for dry sump lubrication.
Oil pan bottom section
Find out more about the cylinder
crankcase.
661_005
5
Crankshaft drive
Crankshaft
Despite higher power output compared to the predecessor
engine, the weight of the crankshaft has been reduced by
3.3 lb (1.5 kg).
Find out more about the crankshaft drive.
The forged and tempered crankshaft is made from steel
(42CrMoS4).
The diameter of the crankshaft main bearings has been
reduced to 2.04 in (52 mm) from 2.28 in (58 mm) which
reduces friction. Drillings in the webs and a longitudinal
drilling provide additional weight savings.
Anti-friction coating on
piston
Connecting rod
(cracked lower ends)
Bore for
weight reduction
Thrust bearing at
5th main bearing
Bore for weight reduction
Crankshaft counterweights
661_006
Main bearing shells
Connecting rod bearing, top/bottom
Due to the stresses exerted on the bearings, an “Irox*
coating” is used on the crankshaft bearing shells.
The small-end bearing shells consist of:
The higher stresses are the result of:
›› A very thin pure aluminum layer acting as a bonding
layer (approximately 1 – 3 µm).
›› Higher ignition pressures.
›› Higher temperatures.
›› Smaller bearing size.
›› A steel back (approximately 0.043 in [1.1 mm]).
›› A polymer coating (approximately 70% PAI + MoS2 as
run-in and dry-run coating).
›› Increased crankshaft flexure.
›› Start-stop system.
Main bearing, top/bottom
The main bearing shells consist of:
›› A steel back(approximately 0.09 in [2.25 mm]).
›› A very thin pure aluminum layer acting as a bonding
layer (approximately 1 – 3 µm).
›› A polymer coating (approximately 70 % PAI + boron
nitride (hard particles) + ferrous oxide Fe2O3 as a wearresistant run-in and dry-run coating).
›› The thrust bearing is located at bearing five.
* Federal mogul polymer coated bearings.
6
Pistons and connecting rods
Cooling duct
Bore for splash oil
Pistons
The pistons have a flat crown which allows higher power
per unit of displacement.
›› A circumferential cooling duct reduces crown temperature by 80 °F (30 °C).
›› Asymmetric shape.
›› The compression ring is located by the integrated ring
land.
›› The piston skirt has a wear-resistant anti-friction
coating.
›› Enlarged valve recesses.
Ring land
Plain rectangular
compression ring
Tapered
piston ring
3-piece oil
control ring
›› The wrist pin axis is offset 0.01 in (0.5 mm) relative to
the center of the piston.
›› The piston and wrist pin are paired.
Piston rings
Bushing
Snap ring
›› Piston ring 1: R
 ectangular ring (upper ring in ring land)
(compression ring))
›› Piston ring 2: Tapered piston ring
›› Piston ring 3: Three-piece oil control ring
Wrist pin
The wrist pins are machined from slug material and coated.
They are manufactured to a high level of precision and
protected by a special silver-colored coating of molybdenum nitride (MoN). This coating is able to withstand higher
stresses.
Upper
bearing shell
Lower
bearing shell
Connecting rod
The forged cracked connecting rod is made of high strength
steel in an I-beam shape. The small end is sleeveless. The
surface is finely honed and roller burnished.
Connecting
rod cap
Stretch bolt
661_007
Reference
For further information about the 3-piece oil control rings, refer to
Self-Study Program 920163, Audi Third Generation 2.0l Engines.
7
Cylinder head
The cylinder head has been revised in many areas compared
with the predecessor engine. As a result of the higher peak
compressive load, a new, five-ply cylinder head gasket is
used in addition to ultra-high-strength cylinder head bolts.
Due to high exhaust gas flow rates, a new exhaust valve
stem seal is used.
Another key feature is the camshaft bearings, which have
been modified to reduce friction.
The Audi valvelift system is used on the exhaust camshaft
of a five-cylinder engine for the first time. A further modification is the relocation of the high pressure fuel pump to
the cylinder block. This results in less vibration being transmitted to the camshaft drive and quicker camshaft adjustment times.
661_008
Key to illustration on page 9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
8
Engine Temperature Control Sensor G694
Cylinder head
Freeze plug
Valve plate
Valve stem
Valve spring
Valve guide
Valve stem oil seal
Upper spring disc
Support element
Roller-type cam follower
Intake valve
Exhaust valve
Camshaft bearing bracket
Inlet camshaft
Exhaust camshaft
17
18
19
20
21
22
23
24
25
26
Cylinder head cover
Camshaft Position Sensor G40
Exhaust camshaft adjuster
Camshaft Position Sensor 3 G300
Exhaust Camshaft Adjustment Valve 1 N318
Camshaft Adjustment Valve 1 N205
Exhaust camshaft adjuster
Intake camshaft adjuster
Valve seat rings
Port divider
Design
20
21
22
19
18
23
17
24
16
15
14
13
12
25
11
10
9
8
7
6
5
4
3
2
1
26
661_009
9
Camshafts
Both camshafts are bolted to the cylinder head cover using
bearing brackets. The advantage of this concept is that of
stress-free installation.
The camshaft mounting forms an integral part of a highly
rigid assembly which makes the engine less susceptible to
vibration at high speeds.
The first bearing behind the chain drive is larger. The cylinder head itself forms the lower bearing surfaces. In the
event of damage, the complete cylinder head must be
replaced.
Camshaft bearing brackets 1 – 5
661_010
AVS camshaft bearing
On the EA855 EVO engine, the camshaft bearing journals
are now directly on the camshaft instead of being on the
sliding cam element.
661_011
EA888 Generation 3
Camshaft bearing journal on the AVS cam element
661_012
Bearing bracket
Note
1. To remove the cylinder head cover, the camshaft timing chain must first be removed.
2. If the camshaft bearings are damaged, the complete cylinder head must be replaced.
10
EA855 EVO
Exhaust camshaft journal
surface on the basic camshaft
Axial camshaft bearing
The camshafts are supported laterally at the bearing
bracket between cylinders three and four.
For this purpose, thrust surfaces are attached to the
camshafts.
661_013
Reluctor ring
and thrust
surface
Thrust surface
exhaust camshaft
Oil channel
Thrust surface
intake camshaft
661_014
11
Audi valvelift system (AVS)
A significant improvement in fuel economy over the previous engine has been achieved by positioning the AVS on the
exhaust side. This also improves the engine torque characteristic. Unlike previous systems, the lift of the exhaust
valves is not adjusted. The two different cam contours only
change event duration, that is the opening time of the
valves.
Operation
The system works in conjunction with the variable valve
timing system. Residual gas is significantly reduced
through phase adjustment of the intake and exhaust camshafts by up to 50° crank angle (phasing angle) on the
intake side and 42° crank angle (phasing angle) on the
exhaust side, as well as by the adaptation of valve opening
duration by the AVS on the exhaust side.
AVS makes it possible to shift between a valve opening
duration of 200° crank angle for medium fuel economy at
low and partial engine loads and a valve opening duration
of 270° crank angle for rapid response and high performance at full throttle.
Cylinder 3 Exhaust Cam Actuator
N595
Cylinder 4 Exhaust Cam Actuator
N603
Actuator pin 2
Exhaust cam adjuster for cylinder 5
N611
Actuator pin 1
Cam element 3
"Power" cam contour
Partial-throttle cam contour
Cam element 4
Y contour
Partial-throttle cam contour
Cam element 5
"Power" cam contour
Recesses for
locating the check ball
Splined basic shaft
Timing side
661_015
Note
If a check nball or a spring is lost due to a cam element being moved too far during repair work, it can be ordered separately.
If the cam element has been forced off the spline, the complete camshaft must be replaced (cam elements fit in any position). In the condition as supplied, the cam elements on a new camshaft are set to the "power" cam contour.
12
Exhaust camshaft design
The cam elements slide on to the splined basic shaft and
are located by a ball and spring. Each cam element is
adjusted by dual actuators, which can move the cam elements in both directions. The cam elements have a
Y-shaped contour at the center.
Each cam actuator now has 2 actuator pins. Pin 1 moves
the cam element to the power cam profile. Pin 2 moves the
cam element to the part throttle profile.
Configuration of the exhaust cam adjusters
Connection
Potential and function
A1
Ground coil 1 = actuator pin 1 = adjustment
of cam element to "power" cam profile
A2
Ground coil 2 = actuator pin 2
in the A3
Terminal 87 voltage supply = adjustment of
cam element to partial-throttle cam profile
"power" cam profile 270° crank angle
661_017
Partial-throttle cam profile 200° crank angle
661_018
Cylinder 3 Exhaust Cam Actuator B
N579
Cylinder 2 Exhaust Cam Actuator
N587
Direction of rotation
Cam element 1
Timing side
Cam element 2
Exhaust
Intake
Reluctor ring
Bearing ring
Spring
Ball
661_016
661_093
Exhaust stroke 200°/10 mm
Exhaust stroke 200°/10 mm (+42°)
Exhaust stroke 270°/10 mm
Exhaust stroke 270°/10 mm (+42°)
Intake stroke 195°/10.7 mm
Intake stroke 195°/10.7 mm (-50°)
Reference
For further information about the working principle of the Audi valvelift system (AVS), please refer to
Self-Study Program 922903, The 2.0L 4V TFSI Engine with AVS.
13
AVS operating range
The cam element is not switched over if the oil temperature
drops below 14 °F (-10 °C) and if an engine speed of
4000 rpm is exceeded. It cannot be switched over until the
engine speed drops below 4000 rpm and the oil temperature is above 159.5 °F (-10 °C).
After the engine is shut off, all cam elements return to the
partial-throttle cam contour.
The system switches over to the "power" cam contour at
mapped operating points at about 3800 rpm and at a
median combustion chamber 159.54 psi (11 bar). The
diagram illustrates this process using an example.
Full throttle
Torque [Nm]
Key:
Camshaft rotation angle
AVS switchover to long-duration event (power)
AVS switchover to short-duration event
(part-throttle)
Engine speed [rpm]
661_019
AVS switchover to long-duration event
AVS switchover to short-duration event
Power cam profile – long-duration event
Partial throttle cam profile - short duration event.
›› Advantages across full throttle range and in terms of
responsiveness.
›› Advantages in terms of fuel efficiency at partial throttle, starting response, raw emissions and running
refinement.
›› Higher torque is achieved at low speeds because this
valve timing configuration allows high scavenging rates
at low engine speeds.
System response to faults
cylinder charging rate is also reduced moderately (this is
not normally noticeable during normal vehicle operation).
In case of faults, the system tries to set all cylinders
equally to an event. If this is the short-duration event, the
System/sensor
Event
Emergency
Engine speed
Can problem
memory entry
operation/
reduction
be remedied?
Lamps
DCY ↗
power reduction
Yes
No
Yes
No
Yes
No
Engine
speed
Yes
Long cam
X
X
X
X
Short cam
X
X
X
X
Combined
operation
X
X
X
X
No
MIL
EPC
X
X
X
X
X
Note
Even if the cam elements are not all set to the short-duration profile after engine repairs, the engine can still be started. The
engine may not run smoothly during the subsequent idling phase, because the control cycles are configured for the shortduration profile. If engine speed is increased to between 1200 and 1800 rpm, the system switches back and forth twice and
reconfigures to the short-duration profile. When installing the exhaust camshaft, therefore, it is important to ensure that
all cam elements are set to the short-duration profile.
14
Exhaust valve stem seal
New valve stem seals were required due to higher exhaust
gas flow rates. The new valve stems are longer than those
of the predecessor engine. The seal design also acts to
center and support the valve springs.
Circumferential valve guide seal
Valve guide
Axial support by valve spring
contact surface
661_020
Cylinder head gasket
›› Five-layer design with two smooth sheet-metal layers at
the top and bottom.
Cover plate
›› Installed height: 0.051 in (1.3 mm).
Upper bead layer
›› Oil bore for cylinder head with flow restrictor function.
Stopper layer
Lower bead layer
661_023
Base panel
Oil bore for cylinder head with
flow restrictor function
661_022
Acoustic insulation for cylinder head
To reduce engine noise levels, a polyether polyurethane
foam insulating panel is located directly above the cylinder
head cover.
661_023
15
Timing assembly
The two stage timing assembly is located on the transmission side of the engine. The engine oil pump and the intermediate shaft are driven by primary chain A. It is an 8 mm
toothed chain. The intermediate shaft is an assembly.
The camshafts are driven by chain B via the intermediate
shaft gear. It is an 8 mm roller chain. The overall chain
drive has been optimized for friction reduction.
Changes to the radii of the chain drive have created a more
compact installation area. This and the switch to a singletrack accessory drive have enabled a 0.07 in (2 mm) reduction to the overall length of the engine.
Advantages:
›› Improved vibration characteristics of the camshafts and
reduced forces in the chain drive.
›› Shorter fuel lines due to positioning on the cylinder
head.
›› Improved package in terms to pedestrian impact mitigation (clearance to hood).
›› System adaptable to increasing fuel pressures as needed
in future applications.
The high-pressure fuel pump drive has been relocated from
the cylinder head to the engine block.
661_026
Lubricating oil supply for:
›› Anti-friction bearing of intermediate
shaft assembly
›› High-pressure pump
661_024
Intermediate shaft with threaded connection on the face.
Non-removable in older engines (pre 2017). This is the first
generation design.
661_025
Intermediate shaft without threaded connection on the face.
Removable, can be bolted together from above, cylinder head
must be removed. This is the second generation design.
16
Find out more about the chain
drive.
Intake camshaft adjuster
›› 30 teeth
›› Adjustment range 50° crank angle
›› After the engine is shut off, the
adjuster is locked in the retard
position by a locking pin
Intermediate shaft assembly
›› Drive for camshafts, high-pressure
pump and vacuum pump
›› Three-lobe cam for high-pressure
pump
›› Press-fitted into cylinder block and
bolted into place
›› Anti-friction bearing
›› Non-removable (first generation only)
›› 24 and 40 teeth
Exhaust camshaft adjuster
›› 30 teeth
›› Adjustment range 42° crank angle
›› After the engine is shut off, the
adjuster is locked in the advance
position by an auxiliary spring loaded
locking pin
Direction of rotation
Sliding rail
Chain tensioner,
hydraulically damped
Tensioning rail
Fuel Metering Valve
N290
High-pressure
fuel pump
Chain drive B
(8 mm roller chain)
Intermediate Shaft Speed Sensor
G265
Chain tensioner, hydraulically damped
Intermediate shaft
bolt coupling
Chain drive A
(8 mm toothed chain)
Chain guide
Crankshaft chain wheel, 25 teeth
Flow-controlled
vane cell oil pump
Chain guide
661_027
Oil pump chain wheel, 24 teeth
17
Accessory belt drive
This allows the engine to be integrated into the Modular
Transverse Matrix without the need for substantial modification of the front body structure.
Unlike its predecessor, a serpentine belt is used for the
accessory units. The purpose of these modifications was
to shorten the overall length of the engine.
Coolant pump drive
4.44 in (113 mm) diameter
Alternator drive
2.55 in (65 mm) diameter
661_029
Vibration damper
6.33 in (161 mm) diameter
Poly-V belt
18
Deflection (idler) pulley
2.75 in (70 mm) diameter
Belt tensioner assembly
2.55 in (65 mm) diameter
AC compressor drive
4.80 in (122 mm) diameter
Vibration damper
The vibration damper is made from aluminum. Damping is
done by a steel ring floating in hydraulic fluid.
Steel inertia
Hydraulic fluid
Bearing rings made from TORLON®
(high-strength amorphous polymer)
Cover
Housing
661_028
Overall length of engine
661_030
19.40 in (493 mm)
19
Positive crankcase ventilation
System overview
1
5
8
3
7
9
4
6
16
15
14
2
12
13
22
21
24
26
25
20
20
19
Key:
Oil return
Blow-by gas
Cleaned blow-by gas
Diagnostic channel
Intake air
Exhaust
Tank ventilation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
10
11
18
Charge air cooler
Non-return valve
Diagnostic channel
Non-return valve
Fuel tank vent
Pressure control valve
Non-return valve
Oil separator module
Throttle flap
Crankcase Ventilation Valve N546
Compressor
Turbine
Cylinder head
Intake ports
Intake manifold bottom section
Intake manifold top section
Vent line for charging mode
Intake line
Exhaust gas side
PCV line
Oil return channel
Crankcase
Air filter housing
Blow-by gas
Gravitational valve
Oil pan
17
23
661_095
21
Vent
Oil separator module
The blow-by gas flows into the cylinder head via the timing
case. Here, oil is separated coarsely from the blow-by gas
by reversing the direction of flow.
The oil separator module serves the following functions:
The oil separator module is flange-mounted to the top of
the cylinder head cover. At this point, engine oil separated
from the blow-by gas before the gas is recycled back into
the combustion air stream.
›› Cylinder block pressure control.
›› Coarse oil separation.
›› Fine oil separation.
›› Blow-by volume flow distribution.
›› By means of non-return valves.
›› To intake side of exhaust turbocharger.
›› To intake manifold.
›› PCV.
›› Activated charcoal filter (ACF) inlet.
Timing case vent
Oil return
Non-return valve
Exhaust side
661_032
22
661_034
Oil return
The oil separated by the coarse oil separator flows into the
cylinder head via ports at the base of the four chambers in
the coarse oil separator and is then recirculated back into
the oil pan.
Camshaft bearing 4
The oil separated by the fine oil separator is recycled back
into the engine's fine oil return channel via a separate port
in the module. This port passes through the cylinder head
as well as the engine block and terminates at a gravitational valve in the oil pan top section. It opens when a
sufficient amount of oil has collected in the return channel
after the engine is shut off.
Oil drain channel from fine oil separator
Fine oil return channel
Suction side
Oil pan top section
661_033
23
Discharge of treated blow-by gases
ports, depending on the pressure conditions in the air
supply system.
The volume flow of the blow-by gases is distributed by the
oil separator module – either to the intake side of the turbocharger turbine or directly into the cylinder head intake
PCV valve
Crankcase Ventilation Valve N546 with integrated non-return valve (closing towards the
intake manifold)
ACF inlet
Evap Canister Purge Regulator Valve 1
N80
The line connection to
the exhaust turbocharger ensures that the
CARB requirements are
met. This line allows
PCV flow while the
engine is under boost.
Blow-by inlet to intake
side of exhaust turbocharger
Intake manifold
661_035
Multi-cyclone
Diaghragm pressure control valve
1.45 psi (100 mbar)
Valve block with:
›› PCV valve diaphragm
›› Non-return valves for crankcase ventilation
Oil separator module
661_036
Cylinder 1
24
Blow-by gas intake upstream of intake side
Positive crankcase ventilation (PCV)
Activated Charcoal Filter (ACF) inlet
To vent the crankcase, fresh air is extracted from the intake
system and introduced into the oil separator module via the
Crankcase Ventilation Valve N546. Here, the fresh air flows
through a diaphragm valve (non-return valve) and into the
crank chamber via a separate channel in the cylinder head
cover, in the cylinder head and in the engine block. N546 is
a solenoid valve which is open when de-energized.
Evap Canister Purge Regulator Valve 1 N80 is closed when
de-energized. Refer to diagram 661_035 on page 24.
The mass flow from the activated charcoal canister is controlled by the ECM based on the duty cycle of N80.
N546 closes under the following conditions:
›› Overrun cut-off.
›› Active mixture adaption.
›› Engine idle.
›› Partial throttle.
For this purpose, the control signal for N546 is calculated
from engine speed, air mass and intake manifold pressure
by the ECM.
The following input variables are evaluated:
›› Intake manifold pressure.
›› Ambient pressure (sensor in ECM).
›› Engine load.
›› Battery voltage.
›› Loading of the ACF canister (evaluation by lambda
control).
During engine operation, N80 is closed under the following
conditions:
›› Over-run cut-off.
›› Stop phases in start-stop mode.
›› Terminal 15 off.
›› Various diagnoses.
Integrated PCV channel
Cylinder 5
661_037
661_038
Integrated PCV channel
PCV transfer point from vent
module (in which a flow
restrictor and non-return valve
(diaphragm) is integrated)
661_039
Oil drain
Fine oil separator
Oil outlets from coarse separator
(baffle plates) in cylinder head
661_040
Blow-by gas intake upstream
of intake side
Oil outlet from cyclone housing;
this oil collects in the chamber of the cyclone separator before the blow-by gas flows
through the cyclone. Additional baffle plates and two diaphragm valves are located
upstream of the cyclone separator. Coarse oil separation also takes place here.
25
Oil separator module
The module together with the coarse separator on its base
protrudes into the cylinder head, where the blow-by gas is
admitted into the system. After oil is separated (coarse
separation) from the blow-by gas at the baffle plates, the
blow-by gas flows through the cyclone separator where it is
finely cleaned. The treated blow-by gas now flows through
the pressure control valve into the section of the ventilation
module where it is is discharged in a controlled fashion via
diaphragm valves, either to the turbocharger or to the
intake ports.
661_041
4-stage cyclone separator with :
›› Bypass valve (opens if flow rate is too high)
›› 2 non-return valves (close in the event of excess pressure in the cylinder
block)
The blow-by gas flows into the chambers of the cyclone
separator. If the flow rate is very high during dynamic
engine operation, the bypass valve opens. This allows a
portion of the blow-by gas to flow past the cyclone separator. This is necessary to ensure that no pressure builds up
inside the crankcase.
PCV connection of
intake manifold
Before the blow-by gas can flow into the cyclone separator,
it first has to flow through a coarse separator upstream,
where it passes through two diaphragm valves. The oil
which collects here then flows into in the separate oil
return line of the cyclone separator. Refer to diagram on
page 24.
Note
Functional faults in the system can cause high oil consumption due to a lack of oil separation or rough engine operation.
Depending on how the PCV is configured, the system can be checked by measuring the pressure at the dip stick. If the system
is intact, a pressure of between -1.23 to 1.74 psi (-85 to 120 mbar) should be realized when the engine is idling.
You can use the turbocharger test V.A.G. 1397A to measure the pressure.
26
PCV transfer point, cylinder head cover
PCV inlet ­­(fresh air from
intake manifold)
661_042
Cleaned blow-by gas to intake port
Diagnostic channel
Cleaned blow-by gas
to turbocharger
to intake port
The adapter is designed in such a way that the diagnostic channel is also
closed by the non-return valve.
to turbocharger
661_043
27
Oil supply
The pistons are cooled by cooling jets which are directed at
the piston crown cooling ducts.
The engine oil circuit is designed for high oil flow rates to
achieve effective cooling. The oil pump has a higher delivery
rate than that of the predecessor engine.
Overview
A
High pressure circuit
Low pressure circuit
B
1
1
1
1
1
1
3
4
5
C
2
2
2
2
2
7
8
8
5
5
6
9
13
13
13
13
5
13
11
14
14
14
14
14
I
14
5
23
24
25
12
8
G
18
18
G10
18
18
15
8
18
17
19
27
10
8
D
H
5
19
19
19
16
19
19
26
8
28
22
22
22
22
22
21
E
20
23
F
30
33
29
32
G266
31
32
31
661_054
Note
The two-stage oil pressure control system will be introduced during 2018.
28
Identification of the engine components
6
3
10
12
1
14
21
20
26
G10
18
19
27
31
G266
30
32
661_055
Key to figures page 28 and page 29:
A
B
C
D
E
F
G
H
I
Cylinder head
Cylinder head cover
Chain tensioner
Primary drive chain tensioner
Vacuum pump
Oil pan
Cylinder crankcase
Oil module
Turbocharger
1
2
3
4
5
6
7
8
9
10
11
12
13
Exhaust camshaft bearing
Support element (exhaust)
Exhaust camshaft adjuster
Exhaust camshaft adjuster lock
Oil screen
Exhaust camshaft timing control valve
Secondary drive chain tensioner
Flow restrictor
Non-return valve in chain tensioner
Intake camshaft timing control valve
Intake camshaft adjuster lock
Intake camshaft adjuster
Support element (intake)
14
Intake camshaft bearing
15
Pressure relief valve, chain tensioner
16
Primary drive chain tensioner
17
Non-return valve in chain tensioner
18
Connecting rod bearing
19
Crankshaft main bearing
20
Vacuum pump bearing
21
Intermediate shaft bearing
22	Piston cooling jet (opening pressure 21.75 psi to 21.6 psi
(1.5 to 1.8 bar), min. closing pressure 20.3 psi (1.4 bar)
23
Non-return valve in oil module
24
Oil cooler bypass valve
25
Oil filter bypass valve
26
Oil/coolant heat exchanger (engine oil cooler)
27
Oil filter
28
Oil drain valve in oil filter module
29
Control valve for low pressure stage
30
Oil pump with two-stage pressure control system
(2018 introduction)
31
Oil pump intake sieve
32
Cold start valve
33
Oil pump with single-stage pressure control system
G10 Oil Pressure Sensor
G266 Oil Level Thermal Sensor
29
Oil pump
The oil pump is bolted to the cylinder block above the oil
pan top section and is driven by the crankshaft via chain by
the crankshaft. A high speed ratio allows the pump to
achieve a maximum speed of 7200 prm. The pump has a
higher delivery rate than in the previous engine.
The oil pump is a vane cell pump with swivelling slide valve
(control valve), which can be rotated against the force of
the control spring by oil pressure, thus altering the volume
of the pump chamber and the delivery rate of the pump.
The oil pressure required for this purpose is diverted from
the main oil gallery and applied to the control surface of
the rotary valve in the pump control chamber.
This pump control system ensures that sufficient engine oil
is always distributed throughout the engine, without an
unacceptable increase in oil pressure.
661_056
Control port ducting pressurized oil from
the main oil gallery into the pump control
chamber
Pump supply
Sprocket
(threaded coupling must
not be unbolted)
Rotor
Vane
Slide control valve
Control spring
Pressure relief valve (cold start valve)
145.03 psi (10 bar)
Reference
For a more detailed explanation of the design and function of the vane cell pump as well as the control function,
refer to Self-Study Program 920173, The Audi 3.0L TFSI EA839 Engine
30
661_096
Sensors in the oil circuit
The 2.5l TFSI engine EA855 EVO does not currently use a
variable oil pressure control system. However, the engine
has all the components needed to provide fully variable oil
pressure control on demand including the necessary castings in the cylinder block. Only one oil pump control valve
needed to be installed in the engine block.
Oil Pressure Sensor G10
G10 is bolted into the oil filter housing and measures both
the oil pressure and the oil temperature in the main oil
gallery downstream of the oil filter (refer to Fig. page 33).
The oil pressure sensor has been installed for its reliability
and functionality. The electronic module integrated in the
sensor sends the data to the ECM by SENT protocol and has
a supply voltage of 5V.
661_057
Oil Level Thermal Sensor G266
Oil Level Thermal Sensor G266 has a 12V supply. It sends a
PWM signal to the ECM.
661_058
31
Oil filter housing / oil cooler
The oil filter housing is attached to the cylinder block and
distributes the engine oil from the oil pump. A portion of
the engine coolant also flows through the housing. Sealing
is done by rubber gaskets. The oil filter cartridge housing is
bolted to the bottom of the oil filter housing. The oil cooler
is also flange-mounted to the oil filter housing. To measure
the engine oil pressure, G10 is integrated in the oil filter
housing.
Oil cooler
Oil Pressure Sensor
G10
Filter cartridge housing
661_059
Oil Pressure Sensor
G10
Oil cooler bypass valve
Oil filter housing
Central pipe
Filter cartridge
Central pipe
Oil ring
Cartridge
housing
Service unit
Tether
Drain valve
The oil can be drained from the filter
housing before removing the filter using oil
drain adapter T40057.
32
Seal
1.41 in (36 mm)
across flats
661_060
Oil flow
The oil delivered by the oil pump flows into the oil filter
housing through a gallery in the cylinder block. The oil
initially flows through the non-return valve, which prevents
the engine galleries from running empty. This allows oil
pressure to build up quickly after the engine starts.
The engine oil flows through the oil filter cartridge from
the outside in. The filtered oil then flows into the oil cooler
before returning to the oil filter housing. From there, the
oil is distributed to the cylinder block and cylinder head.
To ensure the cylinder head always has an adequate engine
oil supply, an additional non-return valve is integrated in
the oil filter housing.
A cooler bypass valve is also mounted to the oil filter
holder. When the cooler bypass valve opens, a portion of
the oil from the oil filter flows to the engine, bypassing the
oil cooler.
Coolant flow
The coolant for the oil cooler enters the connection on the
engine and flows through a duct in the oil filter mount to
the flange mounted oil cooler. The coolant outlet on the oil
cooler is connected to the thermostat housing by a pipe.
Return shut-off valve
Cylinder head
Coolant from engine block
Coolant to oil cooler
From oil cooler
To cylinder head
To cylinder block
Oil flow when oil cooler bypass
valve is open
Return shut-off valve
Main oil flow
Connection of Oil Pressure Sensor
G10
Oil cooler bypass valve opens at
about 19.5 psi (1.35 bar)
From the oil pump
To oil cooler
661_061
Filtered engine oil
33
Cooling system
Overview
2
1
3
4
5
G62
G694
6
7
8
9
V51
10
N82
11
J293
J671
13
12
14
661_062
When the engine is not running and after-run cooling is active, the After-Run Coolant Pump works in combination with
Coolant Shut-Off Valve N82 to reverse the direction of coolant flow.
34
Identification of the engine components
4
G62
G694
5
V51
6
N82
8
7
661_063
Key to figure on page 34:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Coolant expansion tank
Heater heat exchanger
Flow restrictor
Exhaust turbocharger
Cylinder head/engine block
Coolant pump, activated by Mechanical
Coolant Pump Switch Valve N649
Engine oil cooler
Thermostat
Non-return valve
Thermostat for ATF cooler
ATF cooler
Auxiliary radiator
Radiator
Left auxiliary radiator
G62
G694
Engine Coolant Temperature Sensor
Engine Temperature Control Sensor
J293		 Radiator Fan Control Module
J671		 Radiator Fan Control Module 2
N82
Coolant Shut-Off Valve
V51
After-Run Coolant Pump
Cooled coolant
Warm coolant
35
Innovative Thermal Management (ITM)
The purpose of the ITM system is to heat up the engine as
quickly as possible. An active coolant pump is used to
control the flow of heat in the engine during the warm-up
phase.
Two temperature sensors are used to monitor the temperatures in the engine. To ensure that no components are
damaged after the engine is shut off, heat build-up is
prevented by an electrical auxiliary pump. The ITM system
is controlled by the ECM.
Coolant pump
The coolant pump is driven continuously by the crankshaft
by means of a poly V belt.
During the cold start and engine warm-up phases the ITM
system prevents the coolant from circulating within the
cylinder block. A shutter is pulled (by vacuum over) the
pump impeller against the force of compression springs.
This prevents the water pump impeller from circulating
coolant.
Vacuum connection
The vacuum required to activate the coolant pump is controlled by the Mechanical Coolant Pump Switch Valve N649.
The coolant pump impeller is blocked at engine start-up
when the the ambient temperature measured at the cylinder head is between 3.2 °F to 140 °F (-16 °C to 60 °C).
Compression spring
Poly V belt pulley
661_064
Shutter
36
Impeller
661_065
Shutter
Sensors in the coolant circulation system
Engine Temperature Control Sensor G694
Engine Coolant Temperature Sensor G62
An NTC sensor is used to define the component temperature in close proximity to the combustion chamber of
cylinder three in the cylinder head. However, the sensor is
not immersed in coolant. Temperature measurement
range: -40 °F to 365 °F (-40 °C to 180 °C). The ECM requires
the signals generated by the sensor to calculate the afterrun time of After-Run Coolant Pump V51.
G62 measures the coolant temperature in the cylinder
block. It is positioned at the cylinder head outlet. The ECM
requires the signals generated by the sensor to stop the
circulation of coolant during the engine warm-up phase.
The signal is also utilized to calculate various engine maps
and for diagnostics.
Engine Coolant Temperature Sensor
G62
661_066
Engine Temperature Control Sensor
G694
37
Actuators in the coolant circuit
Coolant Shut-Off Valve N82
N82 is a solenoid valve is integrated in the coolant system
and is closed when de-energized. The ECM opens N82
whenever required by switching to ground. At this time,
After-Run Coolant Pump V51 is activated and engine
coolant is circulated to cool the turbocharger. N82 closes
after V51 shuts down.
Coolant Shut-Off Valve
N82
661_067
Mechanical Coolant Pump Switch Valve N649
N649 is an electrical valve powered by the electrical system
and switched to ground by the ECM on demand.
AC compressor
Belt pulley for
coolant pump
Mechanical Coolant Pump Switch Valve
N649
661_068
38
After-Run Coolant Pump V51
This electric auxiliary water pump is activated in order to
protect the exhaust turbocharger against overheating.
It starts to run after a warm engine is shut off.
Run-on function
Depending on the calculation made by the ECM, the pump
runs for the computed amount of time after the engine is
shut off – but not for longer than 600 seconds. In addition,
the radiator fans run at 45%, but not necessarily in combination with V51.
N82 also opens together with V51. If V51 is activated by
the ECM (by PWM signal), it always runs at maximum
speed.
After-Run Coolant Pump
V51
661_069
Reference
For more information about the V51, refer to Self-Study Programs 920173, The Audi 3.0L V6 TFSI Engine and
920243, The Audi 1.8L and 2.0L Third Generation EA888 Engines.
Note
To safely fill and vent the cooling system, it is possible to activate the service position in the Basic setting using the VAS Scan
Tool. The valves in the cooling system are opened at the same time. If VAS 6096/2 is used for evacuating the cooling system,
it is possible to produce more vacuum within the system than before. Due to system design, it is important to warm up the
vehicle and to re-check the coolant level after a test drive because the thermostat only allows flow through the transmission
circuit while driving the vehicle.
39
Air supply and turbocharging
Overview
The air supply system is designed for maximum air flow
rates, low throttle losses and short, direct air flow paths. The
charge air cooler is located low in the vehicle front end and is
able to take full advantage of available ram pressure. The
advantage of this layout provides higher cooling capacity.
Two pressure and temperature sensors are used for measuring air mass: one upstream of the throttle valve, working
in conjunction with Charge Air Pressure Sensor G31; and
one downstream of the throttle valve, working in conjunction with Intake Air Temperature Sensor G42 and Manifold
Absolute Pressure Sensor G71. Both sensors transfer their
signals by SENT protocol.
Intake manifold
The two-part intake manifold is made from a sand-cast
aluminum alloy. A pneumatic flap system is integrated in
the bottom part of the intake manifold. In conjunction with
the tumble inlet duct, it provides the charge motion
required for optimal mixture. The fuel injectors of the MPI
system are also installed here.
The intake manifold top section is configured as a header,
to which the throttle valve control unit is attached by bolts.
Activating the intake manifold flaps
The intake manifold flap vacuum unit is switched by Intake
Manifold Runner Control Valve N316.
At idle and low partial throttle (during normal driving
conditions) the intake manifold flap is closed.
If N316 is not activated by the ECM, and therefore is deenergized, the intake manifold flaps are closed by the force
of the spring in the vacuum unit. The fresh air then flows
into the combustion chambers (halved intake manifold) via
the tumble intake ports in the cylinder head.
During the catalytic converter heating mode, the intake
manifold flaps are closed up to medium engine speed.
Intake Air Temperature Sensor
G42
Manifold Absolute Pressure
Sensor G71
Intake manifold
top section
In both cases, the air mass is factored in as a lesser factor
when calculating the position of the intake manifold flaps.
The position of the intake manifold flaps is monitored by
Intake Manifold Runner Position Sensor G336.
MPI rail
Low Fuel Pressure
Sensor
G410
Intake manifold flap
vacuum unit
Intake manifold
bottom section
Connection to wastegate
intake system
Cylinder 5
661_044
40
Charge Air Pressure
Sensor
G31
Turbocharger
Recirculation Valve
N249
Throttle Valve Control Module
J338
Intake Manifold
Runner Position
Sensor
G336
Intake manifold
flap
MPI injectors
Blow-by gas intake
Intake system
Turbocharger module
PCV fresh air supply
connection
Intake manifold top section
Wastegate connection
Throttle Valve Control Module
J338
Air filter
661_045
Intake manifold flap
vacuum unit
Intake air flow system
Charge air cooler
Pressure section
Intake air flow system
(cold air intake, including water separator)
Find out more about the air
intake system.
41
Turbocharging
Turbocharger module
The turbocharger module is made of cast steel and is rated
for exhaust gas temperatures of up to 1832 °F (1000 °C).
A model-based exhaust gas temperature control system is
used to ensure that this limit is not exceeded. This made it
possible to eliminate an exhaust gas temperature sensor
used in the previous model.
The turbocharger module is attached to the cylinder head
by a clamping flange system, which is an effective way to
compensate for thermal expansion.
The optimal conditions of turbocharger inflow and the low
mass inertia of the turbocharger ensure very high average
pressures and spontaneous throttle response at low engine
speeds.
The conditions of catalytic converter in-flow have also been
improved. To reliably meet emission standards, the catalytic converter is positioned as close as possible to the
turbine housing.
The turbocharger assembly, the compressor and the
turbine have been designed for high efficiency across a wide
operating range, with the result that the rotor assembly
rotates in a different direction than that of the previous
engine.
Intake air flow system
Blow-by gas intake duct upstream
of compressor wheel
Compressor housing
Turbine wheel
Wastegate flap vacuum unit
(charge pressure control)
661_046
Turbine housing
Find out more about the turbocharger.
Wastegate flap
vacuum unit
(charge pressure
control)
Cylinder 5
661_047
42
Charge air pressure control
The charge pressure is regulated up to a maximum boost of
19.6 psi (1.35 bar). This is done by vacuum controlled
wastegate flap. The vacuum unit is activated by Wastegate
Bypass Regulator Valve N75. The wastegate flap is opened
when the vacuum unit is not activated.
Turbocharger Recirculation Valve N249 is installed
upstream of the throttle valve module. (see figure on page
40).
661_048
Wastegate Bypass Regulator Valve
N75
Wastegate flap vacuum unit
(charge pressure control)
Oil and coolant connections
Oil supply pipe
Coolant supply pipe
Coolant return pipe
Oil return pipe
661_049
43
Exhaust system
Overview
The twin-path exhaust system extends from the main
catalytic converter to downstream of the front muffler.
Two secondary catalytic converters are installed downstream of the catalytic converter module.
Broadband oxygen sensor
before catalytic converter
Non-linear oxygen sensor after catalytic
converter
Close-coupled main
catalytic converter
Flexible pipes
(insulating elements)
Secondary catalytic converters
(would metallic catalysts)
Front muffler
(absorption muffler with chrome steel wool and
glass fiber insulation)
Catalytic converter module
The metallic main catalytic converter is positioned as close
as possible to the turbine housing. It is attached to the
turbocharger module by a V-band clamp.
Reference
For more information about the working principle of the exhaust flaps, refer to Self-Study Program
920223, The Audi 4.0L V8 TFSI Engine with Twin Turbochargers.
44
Switchable exhaust valves
In the comfort mode of Audi drive select, the flaps are
closed at idling speed. The right flap is opened with
increasing engine speed. If engine speed is increased still
further, the left flap also opens subsequently.
At higher engine loads both flaps open earlier in order to
achieve a more full-bodied sound in the exhaust system.
In Sport mode the operating points are at lower engine
speeds, that is the flaps open earlier.
The driver can adjust the exhaust gas flaps using the engine
sound button on the center console.
Engine sound button
661_050
Engine sound:
standard
Rear muffler
(reflection silencer)
661_051
Engine sound:
sport
661_052
Exhaust Door Control Unit 2
J945
Exhaust Door Control Unit
J883
661_053
45
Fuel system
Overview
The 2.5l R5 TFSI engine of the EA855 EVO series is
equipped with a combined, on-demand FSI/MPI fuel injection system based on the 2.0l TFSI engines of the EA888
series. The required exhaust emission limits were achieved
by using a dual fuel injection system.
Low pressure rail with MPI injectors
for cylinders 1 – 5
N532 – N536
The FSI injection system is designed for system pressures
of up to 3625.94 psi (250 bar), while the MPI injection
system is rated for 101.52 psi (7 bar).
The single-piston high-pressure pump is driven by a threelobe cam acting on the intermediate shaft of the chain drive.
Low Fuel Pressure Sensor
G410
Fuel feed from fuel delivery
unit in fuel tank
High pressure rail with FSI injectors
for cylinders 1 – 5
N30 – N33, N83
Fuel Metering Valve
N290
High pressure pipe
Fuel Pressure Sensor
G247
High-pressure
fuel pump
661_070
46
Fuel injectors
FSI injector
The electromagnetic FSI fuel injectors are designed for
pressures of up to 3625.94 psi (250 bar). They are installed
in the cylinder head and inject fuel directly into the combustion chamber. The injectors are activated by the ECM,
which applies up to 65 volts. This means it is possible to
have multi-injection pulses and/or to inject extremely small
amounts of fuel.
661_071
MPI injector
The MPI injectors are integrated in the intake manifold
upstream of the intake manifold flaps. When the injectors
are activated (the 12V supply is switched to ground), by the
ECM, fuel is injected continuously into the air flow
upstream of the intake valves.
661_094
Intermediate Shaft Speed Sensor G265
To calculate the injection time for each cylinder, the ECM
requires information about the position and speed of the
high-pressure fuel pump.
The speed and position of the intermediate shaft, and
therefore the three lobed cam, are monitored by a Halleffect sensor. This function was previously done by a camshaft sensor.
661_072
Intermediate shaft encoder disc
661_073
Intermediate Shaft Speed Sensor
G265
47
Combustion process
The development targets for this new engine were:
›› Increased engine power.
›› Better fuel efficiency.
›› Compliance with applicable emission standards.
This has been achieved by using the combined FSI/MPI
injection system.
The broad latitude for selecting injection parameters, in
combination with the intake manifold flaps, makes it possible to bring particulate emissions into compliance with
future emission limits.
Other modifications:
›› Turbocharger output has been increased by:
›› Making optimal use of the exhaust pulsation acting on
the turbine wheel.
›› Revising the exhaust manifold design to minimize
pressure loss.
›› Reversing the direction of rotation of the rotor
assembly.
››
››
››
››
Reducing the residual gas ratio.
Good fuel/air mixture homogenization.
Faster engine warm-up through the use of ITM.
Improving heat dissipation from the combustion
chamber to reduce knock tendency.
›› High compression.
Ignition coils
Exhaust cam adjuster
Exhaust camshaft
Intake camshaft
MPI fuel injectors,
cylinders 1 – 5
N532 – N536
Intake manifold flap
FSI fuel injectors,
cylinders 1 – 5
N30 – N33, N83
High-pressure fuel rail
48
At low engine speeds, FSI fuel injection allows the separation of charge cycles and mixture preparation. This, in
combination with phase adjustment of the intake and
exhaust camshafts as well as exhaust-side event duration
adjustment by the AVS system, greatly reduces the amount
of gas left in the cylinders after gas exchange.
The extension of the intake camshaft phase adjustment
range from 42° crank angle to 50° crank angle represents a
significant improvement.
The increased output of the exhaust turbocharger helps the
engine achieve high volumetric efficiency at low RPM. The
new exhaust turbocharger provides high efficiency at
medium engine speeds.
The intake, pressure and exhaust systems have been carefully coordinated and optimized for pressure loss at high
engine speeds. The MPI injection system ensures that the
required amount of fuel is made available.
Operating modes
›› High-pressure single phase injection.
Warm-up and catalytic converter heating
›› High-pressure dual phase injection.
Example - engine running at heavy load:
›› Dual injection (MPI and FSI).
›› 5% MPI and 95% FSI.
Engine start
Limp-home function
›› Coolant temperature below 113 °F (45 °C) high-pressure
dual phased FSI during the compression stroke.
Example - engine running at light load:
›› Coolant temperature over 113 °F (45 °C): single
phased FSI during the compression stroke.
›› Coolant temperature over 86 °F (30 °C): 50% MPI and
50% FSI.
›› Intake manifold flaps stay closed at near-idle engine
speeds.
Low-pressure rail
Throttle Valve Control Module
J338
Intake manifold top section
High-pressure fuel pump
661_075
49
Engine management
System overview
Sensors
Intake Manifold Sensor GX9 with
Intake Air Temperature Sensor G42 and
Manifold Absolute Pressure Sensor G71
Data Bus On Board Diagnostic
Interface
J533
Charge Air Pressure Sensor GX26 with
Charge Air Pressure Sensor G31 and
Intake Air Temperature Sensor 2 G299
Engine Speed Sensor G28
Throttle Valve Control Module GX3
Camshaft Position Sensor G40
Camshaft Position Sensor 3 G300
Instrument Cluster
Control Module
J285
Accelerator Pedal Module GX2
Brake Light Switch F
Fuel Pressure Sensor G247
Low Fuel Pressure Sensor G410
Fuel Delivery Unit
GX1
Intermediate Shaft Speed Sensor G265
Knock Sensor 1 G61
Knock Sensor 2 G66
Engine Control Module
J623
Engine Temperature Control Sensor G694
Oil Pressure Sensor G10
Oil Level Thermal Sensor G266
Engine Coolant Temperature Sensor G62
Intake Manifold Runner Position Sensor G336
Fuel Tank Pressure Sensor
G400
Oxygen Sensor 1 Before Catalytic Converter GX10
Oxygen Sensor 1 After Catalytic Converter GX7
Additional signal for cruise control system
50
Actuators
Injector, cylinders 1 – 4 N30 – N33
Injector, cylinder 5 N83
Data Link Connector
Injector 2, cylinders 1 – 5
N532 – N536
Ignition coils 1 – 5 with power output stage
N70, N127, N291, N292, N323
Access/Start Authorization
Control Module
J518
Motronic Engine Control Module Power Supply
Relay J271
Engine Component Power Supply Relay 2
J976
Vehicle Electrical System Control Module
J519
Throttle Valve Control Module GX3
Intake Manifold Runner Control Valve N316
Power supply relay
Terminal 15
Fuel Delivery Unit
GX1
Fuel Pump Control Module
J538
Wastegate Bypass Regulator Valve N75
EVAP Canister Purge Regulator Valve 1 N80
Turbocharger Recirculation Valve N249
Crankcase Ventilation Valve N546
Fuel Metering Valve N290
Camshaft Adjustment Valve 1 N205
Exhaust Camshaft Adjustment Valve 1 N318
Exhaust Door Control
Unit
J883
Exhaust Camshaft Actuators for cylinders 1 – 5
N579, N587, N595, N603, N611
Coolant Shut-Off Valve N82
Exhaust Door Control
Unit 2
J945
Fuel Tank Leak
Detection Control
Module
J909
After-Run Coolant Pump V51
Mechanical Coolant Pump Switch Valve N649
Radiator Fan Control Module J293
Radiator Fan V7
Radiator Fan 2 V177
Oxygen Sensor 1 Before Catalytic Converter GX10
Oxygen Sensor 1 After Catalytic Converter GX7
Starter Relay 1 J906
Starter Relay 2 J907
661_074
51
Inspection and maintenance
Service information and operations
Engine oil specification
SAE 5W-30
Quantity of motor oil including filter in
litres (change quantity)
7.5 quarts
Motor oil standard
›› Fixed 10,000 mile service interval VW 502 00 or VW 504 00
Motor oil extraction permitted
Yes
Changing the oil
10,000 miles / 1 year
Inspection
20,000 miles (30,000 km) / 2 years
Air filter change interval
60,000 miles (90,000 km)
Fuel filter change interval
–
Spark plug change interval
60,000 miles (90,000 km) / 6 years
Ribbed V belt replacement interval
Lifetime
Timing assembly
Chain (lifetime)
Special tools and workshop equipment
VAS 5161A/39 Guide plate
T03000A Engine support1)
661_076
For removal and installation of the valve keepers in combination with
removal / installing device VAS 5161A.
T03000/3 Adapter
661_097
Used in combination with engine support T03000A for mounting the
engine and transmission unit in the installed position during engine
removal and installation.
52
661_077
For removal and installation of the engine in combination with engine and
transmission jack V.A.G 1383 A.
T40264/2A Camshaft lock1)
T10122/6A Guide piece1)
661_078
661_079
Ring seal for replacing the crankshaft on the transmission side.
For locking the camshafts to set the valve timing.
T40347 Funnel
T40371 Engine support
661_080
661_081
For reliable installation of the piston in the cylinder.
The high quality of the funnel inner surface protects the sensitive threepart oil control rings of the piston against damage during installation.
For clamping the engine onto the engine and transmission bracket
VAS 6095.
T40376/1 Valve stem seal fitting tool
T40376/2 Valve stem seal fitting tool
661_082
For installation of the new intake valve stem seals.
1)
661_083
For installation of the new exhaust valve stem seals.
A
 s an alternative to these tools, it is possible to adapt older tools already available.
Detailed tool adaptation instructions are given in the workshop manual.
53
Appendix
Glossary
This glossary explains to you all terms which are shown in
italics and indicated by an arrow ↗ in this self study
program.
↗ APS – Atmospheric Plasma Spraying
↗ DIN GZ – Excerpt from DIN 70020-GZ
In atmospheric plasma spraying (APS), spray additives in
the form of particles are applied by means of a plasma jet
to the surface of a substrate to be coated. A plasma is a hot
gas in which neutral particles dissociate and ionize due to
high temperature. Thus, compared to gas, charged particles such as electrons and ions are also present in a plasma.
To produce a plasma, an electric arc is generated between a
cathode and an anode by means of high-frequency ignition
in a plasma burner. At an appropriately selected gas feed, a
concentrated plasma jet with a high heat content is formed
that flows from the nozzle of the plasma burner at high
velocity. The temperatures in the hottest part of the
plasma cone reach about 30,000 K.
This document contains information which is used to determine the engine mass of passenger cars driven exclusively
by internal combustion engines. To make engine masses
comparable, this document specifies which components
are to be considered and disregarded.
The spray powder is introduced into the plasma jet by an
injector. Depending on the process, argon or nitrogen is
used as a carrier gas to deliver the spray powder to the
burner with the necessary kinetic energy. After the powder
is introduced into the plasma jet, the powder particles are
melted and accelerated by the transfer of heat and momentum. Depending on the parameters selected, the powder
particles impinge on the substrate at a certain termperature and temperature.
APS process at Audi
The APS spray coating is applied at Audi's in-house production facility by applying a fine-grained spray powder. To
ensure better layer adhesion, the cylinder bore is mechanically roughened by a toothed profile before the spray
powder is applied. This, in combination with an optimized
honing process, produces small lubrication pockets in the
cylinder liner which allow the piston rings to glide with a
minimum of friction and wear. Further advantages of this
solution are higher heat dissipation compared to cast iron,
resulting in increased knock resistance during the combustion process and improved corrosion resistance to lowquality fuels in the international market.
↗ DCY – Driving Cycle
Faults and substitute reactions can be set and cancelled
during vehicle operation (terminal 15 ON …driving… OFF =
1 Driving Cycle) when fault status debounces "ok" again.
54
Engine mass
An engine with classification G attachment parts is designated as the base engine.
An engine with classification G and Z (GZ) attachment parts
is designated as the complete engine. Classification Z
denotes additional parts.
↗ Rotacast method
The Rotacast method is a tilt casting process variation on
gravity die casting. After being filled with liquid aluminum,
the entire die is swivelled through 180°. The uniform
microstructure distribution ensures that optimal strength
is achieved in both the bearing block and top deck areas.
The aluminum alloy AlSi7Mg0.3 is used. The cylinder block
of the 2.5l R5 TFSI engine is the world's first engine block
to be manufactured using this method.
Self-Study programs
For further information about the 2.5l R5 TFSI engine of
the EA855 EVO series, refer to the Self -Study programs
listed below.
Service Training
Self-Study Program 990713
Audi TT RS with the 2.5L R5 TFSI Engine
SSP 922903
The 2.0L 4V Engine with AVS
The 2.0L 4V TFSI Engine with AVS
Self-Study Program 922903
eSelf-Study Program 920243
SSP 990713
Audi TT RS with the 2.5L R5 TFSI Engine
eSelf-Study Program 920223
The Audi 1.8L and 2.0L Third Generation
EA888 Engines
SSP 920243
The Audi 1.8L and 2.0L Third
Generation EA888 Engines
The Audi 4.0L V8 TFSI Engine
with Twin Turbochargers
SSP 920223
The Audi 4.0L V8 TFSI Engine with
Twin Turbochargers
1
eSelf Study Program 920323
The Audi 3.0l V6 TFSI
EA839 Engine
The Audi 3.0L V6 TFSI
Fourth Generation Engine
SSP 920323
The Audi 3.0L V6 TFSI Fourth
Generation Engine
eSelf Study Program 920173
SSP 920173
The Audi 3.0L V6 TFSI EA839 Engine
2
eSelf Study Program 920163
Audi Third Generation 2.0l Engines
SSP 920163
Audi Third Generation 2.0L Engines
i
55
Knowledge assessment
An On-Line Knowledge Assessment (exam) is Available for this eSelf-Study Program.
The Knowledge Assessment is required for Certification credit.
You can find this Knowledge Assessment at: www.accessaudi.com
From the accessaudi.com Homepage:
›› Click on the “App Links”
›› Click on the “Academy site CRC”
Click on the Course Catalog Search and select “920273 - The Audi 2.5l TFSI Engine EA855 EVO Series”
Please submit any questions or inquiries via the Academy CRC Online Support Form
which is located under the “Support” tab or the “Contact Us” tab of the Academy CRC.
Thank you for reading this eSelf-Study Program and taking the assessment.
56
920273
All rights reserved.
Technical specifications subject to
change without notice.
Audi of America, LLC
2200 Ferdinand Porsche Drive
Herndon, VA 20171