Page 237 of 796
04-6
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 7
*For more information, refer to Chapter "Engine
Control".
2313-01 Air cleaner assembly
Page 238 of 796
04-71719-00
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".
1719-02 Swirl control valve
Operating variably in accordance with the
engine load and rpm.* For more information,
refer to Chapter "Engine Control".
Page 241 of 796

04-10
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.
Page 242 of 796

04-111719-00
LoadEngine
speedSwirl valve Amount of
swirlRemarks
Low speed,
Low loadbelow 3,000
rpmClosed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas)
High speed,
High loadover 3,000
rpmOpen 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. -
-
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.
Page 251 of 796

06-6
3) Inspection of Turbine
Thoroughly check the followings.
Must absolutely not operate the turbocharger with the compressor outlet and inlet opened as it
could damage the turbocharger or be hazardous during inspection.
Interference: In case where is trace of interference or smallest damage on the compressor wheel
means, most of times, that abrasion has occurred on the journal bearing. Must inspect after the
overhaul.
Oil Leakage: The reason for oil leakage at the compressor section is the air cleaner, clogged by
substances such as dust, causes the compressor inlet negative pressure. -
-
Rotating in high speed at no-load for extended period of time can cause oil leakage to the
compressor section as oil pressure within the center housing gets higher than pressure within
the compressor housing.
Overuse of engine break (especially in low gear) in down hill makes significantly low exhaust gas
energy compared to the time where great amount of air is required during idling conditions of the
engine. Therefore, amount of air in the compressor inlet increases but the turbocharge pressure
is not high, which makes negative a.
b.
No problem will occur with the turbocharger if above conditions are found in early stage but oil
leaked over long period of time will solidify at each section causing to breakout secondary defects.
Damages by foreign materials: In case where the compressor wheel is damaged by foreign materials
requires having an overhaul. At this time, it's necessary to check whether the foreign materials have
contaminated intake/exhaust manifold or inside of engine.
Page 256 of 796

06-111914-01
3. TROUBLESHOOTING
The followings are cautions to take in handling defects of turbocharger, which must be fully aware of.
1) Cautions
After stopping the engine, check whether the bolts on pipe connecting section are loose as well as
the connecting condition of vacuum port and modulator, which is connected to the actuator.
During idling of the engine, check for leakage in the connecting section of pipe (hoses and pipes,
duct connections, after the turbocharger) by applying soap water. The leakage condition in the
engine block and turbine housing opening can be determined by the occurrence of abnormal noise
of exhaust.
By running the engine at idle speed, abnormal vibration and noise can be checked. Immediately
stop the engine when abnormal vibration and noise is detected and make thorough inspection
whether the turbocharger shaft wheel has any damages as well as checking the condition of
connections between pipes.
In case where the noise of engine is louder than usual, there is possibility of dampness in the areas
related with air cleaner and engine or engine block and turbocharger. And it could affect the smooth
supply of engine oil and discharge.
Check for damp condition in exhaust gas when there is sign of thermal discoloration or discharge of
carbon in connecting area of the duct.
When the engine rotates or in case where there is change in noise level, check for clogging of air
cleaner or air cleaner duct or if there is any significant amount of dust in the compressor housing.
During the inspection of center housing, inspect inside of the housing by removing the oil drain pipe
to check for sludge generation and its attachment condition at shaft area or turbine side.
Inspect or replace the air cleaner when the compressor wheel is damaged by inflow of foreign
materials.
Inspect both side of the turbocharger wheel after removing inlet and outlet pipe of the turbocharger. 1.
2.
3.
4.
5.
6.
7.
8.
9.
Page 262 of 796

06-171914-01
1. SYSTEM DESCRIPTION OF E-VGT
(Electric-Variable Geometry Turbine)
The E-VGT turbocharger has one shaft where at each ends are installed with two turbines having
different angles to connect one end of housing to the intake manifold and the other end to the exhaust
manifold. As the turbine, at exhaust end, is rotated by exhaust gas pressure the impeller, at intake end,
gets rotated to send air around center of the impeller, being circumferentially accelerated by the
centrifugal force, into the diffuser. The air, which has been introduced to the diffuser having a passage
with big surface, transforms its speed energy into the pressure energy while being supplied to the
cylinder improving the volume efficiency.
Also, the exhaust efficiency improves as the exhaust turbine rotates. The turbocharger is often referred
to as the exhaust turbine turbocharger.
Diffuser: With the meaning of spreading out it is a device that transforms fluid's speed energy into the
pressure energy by enlarging the fluid's passage to slow down the flow.
The E-VGT system installed to the D20DTR engine variably controls the passages of the turbine
housing to regulate the flow rate of the exhaust gas. The actuator of E-VGT is a DC motor actuator
(EActuator) which controls more quickly and precisely than the previous vacuum type actuator.
Page 263 of 796
06-18
Maximizes the intake air charging efficiency (Approx. 15%) -Optimizes the exhaust gas flow rate by controlling the vanes inside the turbine housing with the
EActuator. 1.
(2) E-VGT Actuator (Electric-Actuator)
Target temperature and airflow control
-Enhanced emmission control: By temperature control with CDPF system 1.
(1) Performance (for EURO V)
Has a faster response time than the conventional vacuum actuator. 2.
Improved low speed torque, high speed power and fuel economy.
Improved acceleration performance with rapid response time of vane. -
-
1) Features
Features
Benefits
Folding and unfolding of the vane is
controlled electrically
Easy to get low speed air volume
Rapid response time
Electric control -
-
-
-
Improved low speed torque and
power
Reduced exhaust gas
Improved fuel consumption
Improved acceleration
performance -
-
-
-