76

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Turbocharger oil and coolant connections
The turbochargers are incorporated in the engine oil and
coolant circuits to ensure that the turbine shafts and
bearing are lubricated and cooled.

Coolant circulates through the turbochargers for a defined
period of time after a hot engine has been switched off.
This prevents heat soak and protects the components.

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Coolant supply

Oil return line

Coolant supply line

Coolant return

Heat protection on silicone
hoses below the turbochargers

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77

Heat shield in inner V of engine
The exhaust manifolds are located in the inner V of the
engine (HSI). The adjacent components require protection
to prevent them from becoming too hot. Additional heat
shields are installed for this purpose in the inner V along
with the heat shields on the exhaust manifolds and turbochargers. A heat shield is installed as additional protection
under the engine compartment cover. This cover should
always be in place when the engine is running. You can only
ensure that cool air reaches the inner V of the engine unless
all the components are properly installed.

All supply lines in the inner V are also made of heat-resistant materials (stainless steel, silicone) and in some cases
are installed with additional heat shields. Engine Cover
Temperature Sensor G765 monitors the temperature levels
in the inner V of the engine. If the NTC thermistor registers
temperatures that are too high, the ECM initiates cooling
measures.

Engine compartment cover

Heat shield

Heat shield for oil filter
module

Engine Cover
Temperature Sensor
G765

Side plate

Inner heat shield.
Protects the sensors and
piston cooling jet control
valve

676_121

78

Exhaust system
The exhaust system shown is designed for versions with PR
numbers EU6 AD/E/F (7CN), EU6 plus (7MM), ULEV125
(7MU) and EU4 (7GH).

Oxygen sensor control is done by a broad-band Oxygen
Sensor before the pre-catalytic converter and a two-state
sensor after it. Due to limited space, an additional catalytic
converter is located in the area of the underbody.

GX10

GX7

GX11
GX8

J883

J945

676_100

Key:
GX7 Oxygen Sensor 1 After Catalytic Converter
G130 Oxygen Sensor After Catalytic Converter
Z29 Heater for Oxygen Sensor 1 After Catalytic Converter
GX8 Oxygen Sensor 2 After Catalytic Converter
G131 Oxygen Sensor 2 After Catalytic Converter
Z30 Heater for Oxygen Sensor 2 After Catalytic Converter
GX10 Oxygen Sensor 1 Before Catalytic Converter
G39 Heated Oxygen Sensor
Z19 Oxygen Sensor Heater
GX11 Oxygen Sensor 2 Before Catalytic Converter
G108 Heated Oxygen Sensor 2
Z28 Oxygen Sensor 2 Heater
J883 Exhaust Door Control Unit
J945 Exhaust Door Control Unit 2

79

Fuel system
Fuel is supplied from the fuel tank to high pressure pumps
on the engine by an electric pump. The pressure varies from
43.51 to 79.77 psi (3 to 5 bar). The system does not have a
fuel return line. The amount of fuel required is calculated
by the ECM; the amount supplied is always just enough to
prevent bubbles from forming in the system.

Low Fuel Pressure Sensor G410 in the low-pressure pipe to
monitor the low pressure in the system. Due to the greater
fuel requirement for the V8 engine, each cylinder bank has
its own high-pressure fuel pump. Each cylinder bank has its
own high-pressure supply. The two systems are not connected to one another on the high-pressure side.

Overview of the high-pressure system

Low Fuel Pressure Sensor
G410

Fuel Metering Valve 2
N402

Fuel Metering
Valve N290

Fuel Pressure
Sensor G247

High-pressure
line

Cylinder 4 Fuel Injector
N33

Cylinder 8 Fuel Injector
N86

Cylinder 3 Fuel Injector
N32

Cylinder 7 Fuel Injector
N85

Cylinder 2 Fuel Injector
N31

Cylinder 6 Fuel Injector
N84

Cylinder 1 Fuel Injector
N30

Cylinder 5 Fuel Injector
N83

Fuel Pressure
Sensor 2
G624
High-pressure
rail

676_104

High pressure fuel pumps
The high-pressure fuel pumps are driven by roller tappets
and four-lobe cams positioned on the exhaust camshafts.
The maximum pressure generated is 3625.94 psi (250
bar). At approximately 4351.13 psi (300 bar), the pressure
limiting valve in the pump opens.
The pump is open when no current is applied (fail-safe).
This means that without electric actuation, the pump runs
at the same pressure as the supply from the pump in the
fuel tank.

High-pressure fuel pump
High-pressure
connection

Roller tappet
Four-lobe cams

Exhaust camshaft

676_102

80

High-pressure injector
The injector is positioned directly next to the spark plug.
This central position, together with adjustments to the
injector hole diameter and the spray pattern suited to the
conditions in the cylinder, helps provide the most homogeneous fuel distribution possible.
›
›
›
›
›
›
›

7-hole injector.
Injector hole diameter: 0.007 in (0.19 mm).
Needle lift: 0.0027 in (0.07 mm).
Up to 65 V actuation.
Injection period: 0.3 - 6 ms.
Up to 3 injections possible (depending on engine speed).
Injection pressure: approximately 1015.26 to 3625.94 psi
(70 to 250 bar).

High-pressure fuel pump

Exhaust camshaft
(four-lobe)

Spark plug (spark plug
aperture)

7-hole injector
(positioned centrally in
cylinder head)

Spray pattern of 7-hole
injector (in combustion
chamber)

676_106

Fuel supply rail
connection
Electrical
connection

Injector holes

Cross-section of injector holes

Teflon ring
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676_128

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81

Engine management
System overview

Sensors
Accelerator Pedal Module GX2
Accelerator Pedal Position Sensor G79
Accelerator Pedal Position Sensor 2 G185
Cruise Control Switch E45
Transmission Coolant Valve N488
Oil Pressure Switch F1
Oil Temperature Sensor G8
Tank Ventilation Pressure Sensor 1 G950
Tank Ventilation Pressure Sensor 2 G951
Oil Pressure Sensor G10
Oil Level Thermal Sensor G266
Fuel Pressure Sensor G247
Fuel Pressure Sensor 2 G624
Low Fuel Pressure Sensor G247
Low Fuel Pressure Sensor 2 G624
Engine Coolant Temperature Sensor on Radiator Outlet G83
Engine Cover Temperature Sensor G765
Crankcase Pressure Sensor G1068

Charge Air Pressure Sensor G31
Engine Temperature Sensor G407

Charge Air Pressure Sensor 2 G447
Engine Speed Sensor G28

Camshaft Position Sensors
G40, G163, G300 and G30
Knock Sensors
1-4 G61, G66, G198, G199
Fuel Tank Leak Detection Module GX36

Manifold Absolute Pressure Sensor 2 G429

Exhaust Gas Temperature Sensors G495
and G648
Brake Light Switch F
Brake Pedal Position Sensor G100
(integrated in Brake Light Switch F)
Assembly Mount Sensor 1 and 2 (G748 and G749)
Throttle Valve Control Module GX3
Throttle Valve Control Module J338
Throttle Valve Control Module 2 GX4
Throttle Valve Control Module 2 J544
Exhaust Gas Temperature Sensor 3 Bank 2 G497
Exhaust Gas Temperature Sensor 4 Bank 2 G649

82

Actuators
Starter Relay 1 J906
Starter Relay 2 J907
Comfort System Central
Control Module J393
(Convenience CAN)

Accelerator Pedal Module GXw2
Active Accelerator Pedal Motor V592
Transmission Mount Valve 1 N262
Transmission Mount Valve 2 N263
Transmission Coolant Valve N488

Data Bus On Board
Diagnostic Interface J533

Transmission Fluid Cooling Valve N509
High Temperature Circuit Coolant Pump V467

ABS Control Module
(FlexRay)

Piston Cooling Nozzle Control Valve N522
Assembly Mount Control
Module J931 (Extended
CAN)

Recirculation Valve, Bank 2 N626

Oil Pressure Regulation Valve N428

Fuel Pump Control
Module J538

Ignition Coils 1-4 with Power Output Stage: N70, N127,
N291, N292
Ignition Coils 5-8 with Power Output Stage: N323, N324,
N325, N326
Cylinders 1- 4 Fuel Injectors N30, N31, N32, N33
Cylinders 5-8 Fuel Injectors N83, N84, N85, N86
Fuel Metering Valve N290
Fuel Metering Valve 2 N402

Engine Control Module
J623 (FlexRay)

Mechanical Coolant Pump Switch Valve N649

After-Run Coolant Pump V51
Exhaust Door Control
Unit J883

Exhaust Door Control
Unit 2 J945
Starter-Generator C29
(sub-bus system)

Inlet cam actuator 1 for cylinders 2, 3, 5 and 8
F452, F456, F464, F476
Exhaust cam actuator 1 for cylinders 2, 3, 5 and 8
F454, F458, F466, F478
Crankcase Ventilation Valve N546
Map Controlled Engine Cooling Thermostat F265

VAP Canister Purge Regulator Valves 1 and 2 N80, N115
Camshaft control valves 1 and 2 N205, N208
Exhaust camshaft control valves 1 and 2 N318, N319
Charge Air Pressure Actuators 1 and 2 V465, V546
Radiator Fan Control Module J293
Radiator Fan V7
Radiator Fan Control Module J293
Radiator Fan 2 V177
Assembly Mount Actuators 1 and 2
N513, N514

Throttle Valve Control Module GX3
Throttle Valve Control Module J338
Throttle Valve Control Module 2 GX4
Throttle Valve Control Module 2 J544

676_107

Oxygen Sensor 1 Before Catalytic Converter GX10
Oxygen Sensor Heater Z19
Oxygen Sensor 1 Before Catalytic Converter GX11
Oxygen Sensor 2 Heater Z28
Oxygen Sensor 1 After Catalytic Converter GX7
Heater for Oxygen Sensor 1 After Catalytic Converter Z29
83
Oxygen Sensor 2 After Catalytic Converter GX8
Heater for Oxygen Sensor 2 After Catalytic Converter Z30

Engine Control Module
The engine management system of the EA825 series engines is controlled via Engine Control Module J623 using BOSCH
MG1 software. The ECM processes the incoming system information and controls the various functional groups. It is a node
in the vehicle’s data transfer network.

Data Bus On Board Diagnostic Interface
J533

Engine Control Module
J623

676_124

Starter Generator
C29

676_137

FlexRay
Sub-bus systems

Note

For further information about the engine management system of the EA825 series engines please refer to eSelf-Study
Program 920173, The Audi 3.0L V6 TFSI EA839 Engine
84

Inspection and maintenance
Service information and operations
Engine oil capacity (incl. filter) in liters
(change capacity)

4.3

Service interval

According to service interval display, between 15,000 km/ 1 year and 30,000 km /
2 years depending on driving style and conditions of use.

Engine oil specification

VW 504 00

Engine oil extraction permitted

No (draining only)

Air filter change interval

60,000 miles

Spark plug change interval

40,000 miles (60,000 km) / every 6 years

Fuel filter change interval

–

Timing assembly

Chain (lifetime)

85

Special tools and workshop equipment
Thrust piece T40019/4

Adapter T40320/4

676_108

Accessories for oil seal extractor T40019, for pressing off from
the crankshaft

Cleaning tool T90006

Installing oil seal on crankshaft (pulley end).

Guide plate VAS 5161/43

676_110

For cleaning the injector bores on V6 and
V8 TFSI engines

Adapter T90005

676_146

For removing and installing the valve stem
oil seals with the engine installed

Engine bracket V8 TFSI VAS 6095/1-17

676_111

The adapter is used in conjunction with
T10055 and is used for removing the injector

Engine bracket V8 TFSI VAS 6095/1-18

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86

676_109

676_148

The adapter together with engine and gearbox support VAS
6095A, ASE 456 004 01 000 and universal support VAS 6095/1,
ASE 456 050 00 000 (depending on engine, support for 8-cylinder
TFSI engines).

The adapter together with engine and gearbox support VAS 6095A,
ASE 456 004 01 000 and universal support VAS 6095/1,
ASE 456 050 00 000 (depending on engine, support for 8-cylinder
TFSI engines).

Engine bracket V8 TFSI VAS 6095/1-17A
The new product has some technical modifications, but the previous product can still be adapted for use. The application and adaptation are described in ElsaPro.

Engine bracket V8 TFSI VAS 6095/1-18A
The new product has some technical modifications, but the previous product can still be adapted for use. The application and adaptation are described in ElsaPro.

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 920493 - “The Audi 4.0l V8 TFSI engine from the EA825 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.

87

920493
All rights reserved.
Technical specifications subject to
change without notice.
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2200 Ferdinand Porsche Drive
Herndon, VA 20171