2012 SSANGYONG NEW REXTON engine

1. OVERVIEW
The intake system for D20DTR engine is equipped with a throttle body which includes a flap. This flap is
controlled by an electrical signal to cut off the intake air entering to the engine when the ignition switch is
turned off. Because of this, the shape of the intake manifold has been changed and improved HFM
sensor is newly adopted to control the intake air volume more precisely.
2. COMPONENT
2330-01 Intercooler assembly
2313-15 HFM sensor
HFM sensor, version 6
*For more information, refer to Chapter "Engine
Control".
2313-01 Air cleaner assembly

1719-00
1719-02 Swirl control valve
Operating variably in accordance with the engine
load and rpm.* For more information, refer to
Chapter "Engine Control".
1719-01 Intake manifold
Passage for variable swirl valve and for intake air
1719-16 Electric throttle body
* For more information, refer to Chapter "Engine
Control".

3. INPUT/OUTPUT OF INTAKE SYSTEM
For more information, refer to Chapter " Engine Control". *

1) Types of swirl
Swirl: One cylinder has two intake air ports, one is set horizontally and
the other one is set vertically. Swirl is the horizontal air flows in cylinder
due to the horizontal intake air ports.
Tumble: Tumble is the vertical air flows in cylinder due to the vertical
intake air port
Squish: Squish is the air flows due to the piston head. Normally, this is
appears at the final process of compression. In CRDi engine, the
piston head creates the bowl type squish.
2) Swirl control
In DI type diesel engine, the liquefied fuel is injected into the cylinder directly. If the fuel is evenly
distributed in short period, the combustion efficiency could be improved. To get this, there should be
good air flow in cylinder. In general, there are two intake ports, swirl port and tangential port, in each
cylinder. The swirl port generates the horizontal flow and the tangential port generates the longitudinal
flow. In low/mid load range, the tabgential port is closed to increase the horizontal flow. Fast flow
decreases the PM during combustion and increases the EGR ratio by better combustion efficiency.

1719-00
LoadEngine speed Swirl valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000 rpm Closed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas)
High speed,
High loadover 3,000 rpm Open LightIncrease charge efficiency, higher
engine power
The variable swirl valve actuator operates when
turning the ignition switch ON/OFF position to
open/close the swirl valve. In this period, the soot
will be removed and the learning for swirl valve
position is performed.
Swirl: This is the twisted (radial) air flow along the cylinder wall during the intake stroke. This
stabilizes the combustion even in lean air-fuel mixture condition.
Swirl valve
3) Features
Swirl and air intake efficiency
To generate the swirl, the intake port should be serpentine design. This makes the resistance in air
flow. The resistance in air flow in engine high speed decreases the intake efficiency. Eventually, the
engine power is also decreased, Thus, the swirl operation is deactivated in high speed range to
increase the intake efficiency.
Relationship between swirl and EGR
To reduce Nox, it is essential to increase EGR ratio. However, if EGR ratio is too high, the PM also
could be very higher. And, the exhaust gas should be evenly mixed with newly aspired air. Otherwise,
PM and CO are dramatically increased in highly concentrated exhaust gas range and EGR ratio
could not be increased beyond a certain limit. If the swirl valve operates in this moment, the limit of
EGR ratio will be higher. -
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4) Relationship between swirl and fuel injection pressure
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If the
swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when the
swirl is too strong.

2. CAUTIONS
Do not park the vehicle on flammable materials, such as grass, leaves and carpet.
Do not touch the catalyst or the exhaust gas ignition system when the engine is running.
If a misfire occurs in the combustion chamber or the emission of pollutant exceeds the specified
level, the catalyst can be damaged.
When servicing or replacing components of the exhaust system, makes sure that the components
are positioned at regular intervals from all other parts of the under body.
Be careful not to damage the exhaust system when lifting the vehicle from its side.
All components and body parts of the engine exhaust system should be inspected for crack,
damage, air hole, part loss and incorrect mounting location. Also check for any deformation which
can result in exhaust gas drawn into the vehicle.
Make sure that the exhaust pipe is cooled down sufficiently before working on it because it is still hot
right after the engine is stopped.
Wear protective gloves when removing the exhaust pipe. -
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1729-01
Exhaust manifold assembly
CDPF assembly
1. OVERVIEW
This system purifies the exhaust gas generated by the combustion in the engine to reduce the pollutants
and noise during that arise during combustion.
2. LAYOUT
Exhaust front pipe assembly
Muffler assembly
Exhaust tail pipe assembly
For more information, refer to Chapter
"Engine Control". *

2. INSPECTION
1) Cautions During Driving
The following lists cautions to take during test drive and on the turbocharger vehicle, which must be
considered during the operation.
It's important not to drastically increase the engine rpm starting the engine. It could make rotation at
excessive speed even before the journal bearing is lubricated and when the turbocharger rotates in
poor oil supply condition, it could cause damage of bearing seizure within few seconds.
If the engine is running radically after replacing the engine oil or oil filter brings poor oil supply
condition. To avoid this, it's necessary to start off after idling the engine for about 1 minute allowing oil
to circulate to the turbocharger after the replacement.
When the engine is stopped abruptly after driving at high speed, the turbocharger continues to rotate
in condition where the oil pressure is at '0'. In such condition, an oil film between the journal bearing
and the housing shaft journal section gets broken and this causes abrasion of the journal bearing due
to the rapid contact. The repeat of such condition significantly reduces life of the turbocharger.
Therefore, the engine should be stopped possibly in the idle condition. 1.
2.
3.
After string for long period of time during winter season or in the low temperature condition where the
fluidity of engine oil declines, the engine, before being started, should be cranked to circulate oil and
must drive after checking the oil pressure is in normal condition by idling the engine for few minutes.