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05-51729-01
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". *
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06-4
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.
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06-50000-00
2) Inspection of Turbocharger
When problem occurs with the turbocharger, it could cause engine power decline, excessive
discharge of exhaust gas, outbreak of abnormal noise and excessive consumption of oil.
On-board Inspection 1.
Check the bolts and nuts foe looseness or missing
Check the intake and exhaust manifold for looseness or damage
Check the oil supply pipe and drain pipe for damages
Check the housing for crack and deterioration -
-
-
-
Inspection of turbine 2.
Remove the exhaust pipe at the opening of the turbine and check, with a lamp, the existence of
interference of housing and wheel, oil leakage and contamination (at blade edge) of foreign
materials.
Interference: In case where the oil leak sign exists, even the small traces of interferences on
the turbine wheel mean, most of times, that abrasion has occurred on the journal bearing.
Must inspect after overhauling the turbocharger.
Oil Leakage: Followings are the reasons for oil leakage condition -
-
Idling for long period of time can cause oil leakage to the turbine side due to low pressure of
exhaust gas and the rotation speed of turbine wheel. Please note this is not a turbocharger
problem.
Oil Drain Pipe Defect
In case where oil flow from the turbocharger sensor housing to the crank case is not smooth
would become the reason for leakage as oil builds up within the center housing. Also, oil
thickens (sludge) at high temperature and becomes the indirect reason of wheel hub section. In
such case, clogging and damage of the oil drain pipe and the pressure of blow-by gas within
the crank case must be inspected.
Damages due to Foreign Materials
When the foreign materials get into the system, it could induce inner damage as rotating
balance of the turbocharger gets out of alignment. -
-Problems in engine: In case where the oil is smeared on inner wall section of the exhaust
gas opening.
Problems in turbocharger: In case where the oil is smeared on only at the exhaust gas
outlet section. *
*
Page 226 of 828

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.
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06-91914-01
Turbine Side: Inflow of foreign materials from engine
Compressor Side: such as air filter, muffler and nut 3.
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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 237 of 828

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.
1) Overview
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 (E-Actuator) which controls more quickly and precisely than the previous vacuum type
actuator.
The engine ECU controls the E-Actuator electronically as follows:
At low speed: Narrows the flow passage for the exhaust gas, resulting in increasing the
flow speed of the exhaust gas and running the turbine quickly and powerfully.
At high speed: Expands the flow passage for the exhaust gas, resulting in increasing the
mass flow of the exhaust gas and running the turbine more powerfully. -
-
Page 239 of 828
06-191914-01
T-MAP sensor
Booster pressure and
temperature
E-VGT turbocharger
Improves engine power
2. COMPONENTS
Engine ECU (D20DTR)
E-VGT duty controlAccelerator pedal position
sensor
Transfers driver's will to
accelerate to ECU
Atmospheric pressure, RPM
signal
HFM sensor
Improves the engine powerCoolant temperature sensor
Operates the VGT according
to engine warm-up
* 세부제어로직은 엔진제어편 참조