Contact surface

Exhaust Camshaft Adjustment
Valve 1 N318

Camshaft Adjustment Valve 2
N208
Exhaust Camshaft Adjustment Valve 2
N319

Camshaft Position
Sensor G40

Tensioning rail

Camshaft Adjustment Valve 1
N205

Guide rail

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Basic positions for crankshaft/camshaft timing
The engine is in its basic position when cylinder 1 is at TDC position and the crankshaft can be locked in place. The markings
on the camshaft adjusters must be opposite the corresponding projections on the camshaft housing. The camshaft adjusters
must be positioned precisely, as the drive chain sprockets are tri-oval shaped. These tri-oval chain sprockets make it possible
to minimize the dynamic forces from the valve gear and allow the engine to run more smoothly.

Marks for basic setting

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Locking the crankshaft
The crankshaft can be locked in two ways, as described below.
With the engine installed in the vehicle using lock in pin T10492

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Locking pin T10492

With the engine removed using lock in pin T40069

Engine bracket

Locking pin
T40069

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Water pump drive shaft
The water pump drive shaft is mounted in sleeve bearings and is driven by a tensioning gear via the crankshaft.

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34

Tensioning gear
The tensioning gear must be pre-tensioned during installation using Locking Pin T40362.

Coolant pump drive shaft

Tensioning gear

Coolant pump drive gear

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35

Crankcase ventilation system
The crankcase is vented above the cylinder head covers. An oil separator module is bolted onto each cylinder head cover for
this purpose. The filtered blow-by gases are also channeled separately for each cylinder bank. The inlet points are located
upstream of the intake side of the turbocharger turbines (discharge at full load) as well as in the intake manifold of the
cylinder heads (discharge at partial load).
Intake is regulated by non-return valves which open or close independently depending on the pressure level in the air
supply. A non-return valve is installed in the breather line from the oil separator to the connection in front of the turbocharger turbines. The second non-return valve is installed in the corresponding oil separator module.

Oil seperator,
bank 2

Non-return valve

Non-return valve
Oil seperator,
bank 1

Breather line,
full load

Breather line,
partial load

Breather line,
partial load

Breather line,
full load

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The ECM regulates the crankcase ventilation system. The
system must be capable of discharging approximately 3.53
cu ft (100 L) of blow-by gases from the crankcase without
loosing oil in the process.

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Blow-by discharge at partial load
On both cylinder banks, the filtered blow-by gases flow from the oil separator into the corresponding intake manifold. At
low air temperatures and high flow speeds, the blow-by mass flow is heated in the intake manifold to prevent it from
freezing under extreme conditions.
A PTC heater element is installed at the connection between the breather line and the intake manifold. It is controlled by
the ECM via a PWM signal based on a calculated characteristic map.
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›

Positive Crankcase Ventilation Heating Element N79 cylinder bank 1 (right-side)
Crankcase Ventilation Thermal Resistor 2 cylinder bank 2 (left-side)

Heater element for
crankcase ventilation

N483
N79

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Oil separator
The blow-by gases flow out of the crankcase and into the cylinder head area via channels in the crankcase. From there, the
blow-by enters an inlet plenum chamber in the cylinder head cover; this is where the oil separator is installed. When the
engine is running, oil that has been separated collects in the collection chamber of the oil separator.

Pressure regulating valve .23 psi
(85 mbar)

Connection for
intake manifold

Connection for
turbocharger

Non-return valve
Opens in
partial-load
operation

Oil separator
(impactor)

Non-return valve
Opens in full-load
operation
Blow-by inlet

Oil return channel

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When the engine is not running or when a defined level in the oil separator is exceeded, the gravity valve opens and the oil
drains into the crankcase. The gravity valve also prevents oil from the sump from entering the oil separator in the event of
large fluctuations in pressure, for example due to sudden load change.

Oil return valve
(gravity valve)

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Reference

For more information about the oil separator, please refer to eSelf-Study Program 920173, The Audi 3.0L V6
TFSI EA839 Engine.
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Oil return
The separated oil in the oil separator collects in the cylinder head cover tray (located below the oil separator). It is
directed through a drilled channel down to the inlet side and then enters the valve chamber of the cylinder head via the
oil discharge valve.

Oil discharge valve
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Engine breather
passages (inside)

Oil return channels (outside)
cylinder heads over crankcase
in sump
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The oil flows into the sump via separate return channels. The inlet point is located below the oil surface level.
Oil return channels (outside)
cylinder heads over crankcase in sump

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Positive Crankcase Ventilation (PCV)
Positive crankcase ventilation (PCV) takes place when
charge pressure is present. The air flow which is channeled
into the crankcase in this process is limited by defining the
cross-section of the pipe in the crankcase connection. In
certain operating modes, for example, to avoid blow-by
gases when mixture adaption is active, Crankcase Ventilation Valve N546 is actuated, which regulates the flow of
fresh air.

Two non-return valves are installed for security. They close
when the difference in pressure between the air system and
the crankcase becomes too great; otherwise the vacuum
pressure inside the crankcase could become too high. The
non-return valves are located in N546 and in the connection on the crankcase.

The fresh air intake point for the crankcase is located in
front of the throttle valve for cylinder bank 2. Air is drawn
into the crankcase at a connection just above the upper
sump on the left side of the engine.

Crankcase Ventilation Valve
N546

Fresh air intake

Fresh air extraction before
throttle valve

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Crankcase
connection

Crankcase Ventilation
Valve N546

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Crankcase connection
with non-return valve
and throttle function

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Fuel tank ventilation
Fuel tank ventilation is controlled by Engine Control Module
J623. It is done by regulating the vapor flow from the
charcoal canister via EVAP Canister Purge Regulator Valve 1
N80 and EVAP Canister Purge Regulator Valve 2 N115.

When there is a vacuum in the intake manifold, the
activated charcoal filter is vented via the non-return valves
in the intake manifold. When there is charge pressure,
venting takes place on the intake side in front of the
turbocharger.

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Tank Ventilation Pressure
Sensor 1
G952

From activated charcoal filter

EVAP Canister Purge Regulator
Valve 1
N80

EVAP Canister Purge
Regulator Valve 2
N115

Connection to intake manifold for
cylinder bank 1 with non-return
valve at partial load

Discharge to intake side of turbocharger at full load with assistance from suction-jet pumps

Tank Ventilation Pressure
Sensor 2
G951

Connection to intake
manifold for cylinder
bank 2 with non-return
valve at partial load
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Tank Ventilation Pressure Sensors 1 and 2 are mounted
upstream of the EVAP Purge Regulator Valves. They are
used to check whether sufficient vacuum is present in the
fuel tank ventilation lines.
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If a ventilation line is disconnected or leaky, a pressure drop
would not be measurable and the MIL would be switched on.

Suction-jet pumps for fuel tank breather system
During times when no vacuum is present in the intake
manifold, the fuel tank ventilation system discharges into
the turbocharger compressor housings. This is assisted by
suction-jets operating on the Venturi principle. The suction-jets utilize the pressure gradient between the pressure
and the intake sides of the compressor. The accelerated air
flow produces a vacuum which is used to ventilate the
charcoal canister.

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Each suction-jet pump is connected to the intake side
(vacuum) and the pressure side of the turbocharger. Once
there is a sufficient difference in pressure between the
intake side and the pressure side, for example, at full load,
a “Venturi effect” is created. This extracts the fuel vapors
from the activated charcoal filter and directs them into the
intake side of the turbocharger.

Intake side
Turbocharger

Pressure differential

Venturi nozzle

Non-return valve
from activated
charcoal filter

Pressure side
Turbocharger
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Vacuum system
Vacuum pressure is created by a single-vane pump driven by the inlet camshaft for cylinder bank 2.
The vacuum pump must supply the following components with vacuum pressure:
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›
›

The mechanical coolant pump: to ensure standing coolant in the cylinder block when the engine is warming up.
The vacuum units of the turbocharger: to close the bypass flaps thus regulating the charge pressure.
The brake servo.

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Charge Air Pressure Actuators V465 and V546 are electro-pneumatic exhaust gas recirculation valves. They are able to
initiate a calculated vacuum pressure (characteristic curve) according to the actuation (PWM) by the ECM. This determines
the degree to which the bypass flaps are open; they are open when not actuated.
Mechanical Coolant Pump Switch Valve N649 is an electric changeover valve. It can only be switched to “on” and “off”.

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Connection for vacuum unit/
turbocharger
Pressure equalization hose to
prevent turbocharger pumping

Direction of flow

Non-return valve

Connection for
mechanical coolant
Charge Air Pressure
pump
Actuator V465
Connection for
brake servo
Mechanical
Coolant Pump
Switch Valve
N649

Connection for
vacuum reservoir

Shaft driven
engine coolant
pump

Outlet (vacuum
pressure input)

Oil Pressure Sensor
G10

Vacuum pump

Charge Air Pressure
Actuator 2
V546

Open when actuated;
otherwise closed

Always open

Open when not
actuated; closed when
actuated

180 cm3 single-vane
vacuum-pump with axial
elastomer seal

A sinterred plastic air filter is
installed because the breather
connection is within reach of
water spray (cannot be replaced
separately)

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Pressure equalization between the vacuum units of the bypass flaps
If there are differences between the characteristic curves of the two charge pressure positioners, this could cause the
vacuum units to be actuated differently and create different pressure levels in the turbochargers, leading to undesired
noises (turbocharger pumping). A connecting pipe equalizes the pressure between the vacuum connections of the vacuum
units of both turbochargers.

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Oil supply
The key objectives for the oil circuit development are to keep pressure losses to a minimum and ensure optimal flow.
Key technical features of the oil circuit are:
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›
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Fully variable map-controlled vane cell oil pump.
Piston cooling jets which inject directly into the piston crown cooling ducts.
Thermostat controlled engine oil cooler.

Oil circuit overview

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Key:
A
B
C
D

Cylinder head 1
Cylinder block
Cylinder head 2
Cylinder head gallery

1
2
3
4
5
6
7
8
9
10
11
12
13

Oil pan
Oil Level Thermal Sensor G266
Oil intake with strainer
Oil pump
Oil-coolant heat exchanger (engine oil cooler)
Oil filter
Turbocharger
Bypass valve
Turbocharger non-return valve
Connecting rod
Pressure relief valve (cold start valve)
Oil Pressure Regulation Valve N428
Oil Pressure Sensor G10

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14
15
16
17
18
19
20
21
22
23
24
25
26

Intermediate shaft bearing
Oil gallery for piston cooling jets
Oil Pressure Switch F22
Oil Temperature Sensor G8
Piston Cooling Nozzle Control Valve N522
Chain tensioner
Camshaft adjuster
Camshaft control valves
Camshaft bearings
Vacuum pump
High-pressure fuel pump
Hydraulic valve clearance compensation element
Oil drain valve

Overview of engine components

Oil heat exchanger

Oil filter module

Oil supply gallery for
components in the
cylinder head

Main oil gallery for crankshaft
bearing lubrication

Supply gallery to oil/coolant
heat exchanger

Control gallery to oil pump

Oil pump

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Oil pump
Drive
The vane cell oil pump is driven by the crankshaft via a
chain drive on the front side of the engine. A 7mm chain
and leaf-spring chain tensioner (no hydraulic damping) is
used. A guide rail is installed on the driving side of the
pump due to the distance between the shafts for the chain
sprockets.

Oil Pressure
Regulation Valve
N428

Coolant pump drive