warm-up phase. This is necessary because the coolant in
proximity to the integral exhaust manifold would otherwise
boil off very quickly. For this reason, Engine Coolant Temperature Sensor G62 is installed at the hottest point in the
cylinder head.

Intake side

Main water jacket

Upper coolant tract

Lower coolant tract

Exhaust gas duct with flange
connecting to turbocharger

Exhaust side

606_032

Animation showing the cylinder head
and the integral exhaust manifold.

22

Positive crankcase ventilation
The positive crankcase ventilation system has also been
systematically improved. The cylinder block pressure to
ambient air pressure ratio is configured for a high pressure
gradient.
A strong emphasis has been placed on reducing the number
of components. On the exterior of the engine, for example,
there is now only one pipe for the discharge of cleaned
blow-by gases.

The system comprises the following components:
• Coarse oil separator integrated with cylinder block
• Fine oil separator module, bolted onto the cylinder
head cover
• Hose for the discharge of cleaned blow-by gases
• Oil return line in the cylinder block with shutoff valve
in the oil pan honeycomb insert

Entry of blow-by gases into the intake manifold module
(in naturally aspirated mode)
Entry of blow-by gases into the turbocharger
(in charging mode)
Fine oil separator module

Oil return duct from
the fine oil separator

Oil return line shut-off valve
Coarse oil separator
for the fine oil separator
(below the oil level in the oil pan)

Oil return duct from the fine oil separator
(below the oil level in the oil pan)

606_043

23

Coarse oil separation
The coarse oil separator function is an integral part of the
cylinder block. A portion of the oil is separated by changing
the direction of oil flow in a labyrinth.

The separated oil returns to the oil pan via the return duct in
the cylinder block. The end of the duct is below the oil level.

Fine oil separation
The coarsely cleaned blow-by gases flow from the cylinder
block into the fine oil separator module through a duct in
the cylinder head.
Here, the gases are cleaned in a cyclone separator. The
separated oil from the cyclone separator returns to the oil
pan through a separate duct in the cylinder block. The end of
this duct is below the oil level.
A shutoff valve prevents oil from being drawn in from the oil
pan in unfavorable pressure conditions.

Bypass valve
opens at excessively high blow-by
flow rates (very high engine speed)
oil is also separated here by the
high flow rate

A sporty driving style (high transverse acceleration) could
potentially expose the immersed oil return line because of
the oil sloshing inside the oil pan. In this case, too, the
shutoff valve keeps the oil return line closed. The shutoff
valve is a shutter-type valve.
The cleaned blow-by gases are directed into the combustion
chamber via the single-stage pressure control valve. The
pressure control valve is rated for a pressure difference of
-1.45 psi (-100mBar) relative to the ambient air. The point at
which the blow-by gases are admitted into the combustion
chamber is dictated by the pressure ratio in the air supply
system.

Pressure control valve

Connection to carbon
canister

606_045

Blow-by duct from the
cylinder block and cylinder
head

24

Cyclone separator

Blow-by line to
turbocharger
(charging mode)

Supply of cleaned blow-by gases to the combustion chamber
After the blow-by gases have been cleaned of fine oil droplets and allowed to flow through the pressure control valve,
they are admitted into the combustion chamber. Gas flow is
controlled automatically by self-actuating non-return valves
integrated into the fine oil separator module.

The non-return valves return to their initial position when
the engine is shut off. The non-return valve facing the
exhaust turbocharger is open, while the non-return valve
facing the intake manifold is closed.

Faulty installation detection

Full throttle operation (charging mode)

Emission regulations require that safeguards be provided to
detect faulty installation of these components.

Since pressure is now present throughout the charge air
tract, non-return valve 1 closes.

If the venting line on the crankcase breather module is not
installed (or not properly installed) an installation detection
contact opens.

The difference between the pressure inside the crankcase
and the pressure on the intake side of the turbocharger
causes non-return valve 2 to open.

This contact is connected directly to the air intake side of the
cylinder head. The engine immediately begins to induct
unmetered air which is detected by the oxygen sensors.

The cleaned blow-by gases are inducted by the compressor.

Bypass valve

Cyclone
separator

Non-return valve 2
(open)

Non-return valve 1
(closed)
606_047

Blow-by passage to turbocharger
(charging mode)

25

Idle and partial throttle operation (naturally aspirated mode)
In naturally aspirated mode, non-return valve 1 is opened by
the vacuum present in the intake manifold and non-return
valve 2 is closed.

The cleaned blow-by gases are admitted directly into the
combustion chamber via the intake manifold.

Blow-by gas intake

Pressure control valve

Blow-by passage to intake manifold (naturally aspirated mode)

606_046

PCV valve

26

Non-return valve 2
(closed)

Non-return valve 1
(open)

Positive crankcase ventilation
The crankcase breather is installed in a module on the
camshaft cover together with the fine oil separator and
the pressure regulator.

The crankcase is vented via the venting line connected
upstream of the turbine and a calibrated port in the crankcase breather valve.
The system is therefore designed in such a way that it is only
vented when the engine is running in naturally aspirated
mode.

Connection to carbon
canister

Calibrated bore for
positive crankcase
ventilation
PCV valve diaphragm
(removed)

Blow-by line to intake manifold
(naturally aspirated mode)

Cyclone separator

Blow-by gas intake

606_083

27

Oil supply

Bearing bridge
A

System overview
Key:
A

Camshaft bearing

B

Support element

C

Balancer shaft bearing

D

Exhaust balancer shaft bearing 1

E

Connecting rod

F

Main bearings 1 – 5

1

3

1

Exhaust Camshaft Adjustment Valve 1 N318

2

Hydraulic vane cell adjuster (exhaust)

3

Non-return valve, integrated. into bearing bridge

4

Mesh oil filter

5

Camshaft Adjustment Valve 1 N205

6

Hydraulic vane cell adjuster (intake)

7

Non-return valve, integrated into cyl. head

8

Fine oil separator

9

Vacuum pump

10

Flow restrictor

11

Lubrication of cam for high pressure fuel pump

12

Oil cooler

13

Non-return valve, integrated into oil filter

14

Oil filter

15

Oil drain valve

16

Oil Pressure Switch F22 33.3 - 43.5 psi (2.3 - 3.0 bar)

17

4

5

3
A
6

4

Reduced Oil Pressure Switch F378 7.25 - 11.6 psi
(0.5 - 0.8 bar)

18

Piston Cooling Nozzle Control Valve N522

19

Mechanical switching valve

20

Chain tensioner for balancer shafts

21

Chain tensioner for timing gear

22

Turbocharger

23

Coarse oil separator

24

Oil Pressure Switch Level 3 F447

25

Lubrication of gear step

26

Oil Level Thermal Sensor G266

27

Cold start valve

28

Non-return valve, integrated into oil pump

29

Regulated oil pump

30

Oil Pressure Regulation Valve N428

Auxiliaries mounting
bracket

12

13

14

18
16

15

17

19

High pressure circuit
Low pressure circuit

Oil pan top
section
28

29
30
27
26
4
Oil pan bottom section
28

A

2

8
Oil channels

A

A

A

A

9

A

4
B

B

B

B

B

B

B

10
11

B

Vacuum pump

B

B

B

A

B

B

A

B

B

A

B

A

7

Cylinder head

20

21

22

D

C

23

F

E

C

E

F

E

F

C

F

E

F

24
4

C

4

C

C

25
Cylinder block

606_018
29

Oil supply
The engine lubrication system has been redesigned. The
main points are:

•
•
•
•
•

Together, these modifications have reduced friction within
the engine assembly thus improving fuel economy still
further.

Optimization of the pressure ducts in the oil system,
reducing pressure losses while simultaneously
increasing volume
Reduction of pressure losses in the pressurized
oil galleries
Extension of the rpm range in the low pressure stage
Oil pressure reduction in the low pressure stage
Switchable piston cooling jets
Oil Pressure Switch Level 3 F447
Oil cooler

Oil filter

Reduced Oil Pressure
Switch F378

Oil Pressure
Switch F22

Piston Cooling
Nozzle Control
Valve N522

Auxiliaries mounting bracket

Oil Pressure Regulation Valve
N428