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02-490000-00
The bottom side of water jacket is desgined as sine wave to strengthen the structure of crankcase.
The main flow of coolant starts from outlet port of water pump and goes along the longitudinal
direction of engine. The coolant passage from cylinder head to inlet port of water pump is
integrated in cylinder head.
The engine oil from oil pump is supplied to the main oil gallery through oil channel, oil filter
module and cross bore in cylinder block without using external pipes. This oil is supplied to main
bearing, cylinder head and MBU. And, it is sprayed to the chain through the chain tensioner
connected to cross bore.
Crankcase cross bore for oil supply
Water jacket core
Page 208 of 715
03-4
Took kit for low pressure lineTool kit for high pressure line
2. MAINTENANCE AND INSPECTION
1) Maintenance Procedures for DI Engine Fuel System
Always keep the workshop and lift clean (especially, from dust).
Always keep the tools clean (from oil or foreign materials).
Wear a clean vinyl apron to prevent the fuzz, dust and foreign materials from getting into fuel
system. Wash your hands and do not wear working gloves. 1.
2.
3.
Follow the below procedures before starting service works for fuel system.
If the problem is from HP pump, fuel supply line or injector, prepare the clean special tools and
sealing caps to perform the diagnosis for DI engine fuel system in this manual. At this point,
thoroughly clean the related area in engine compartment. 4.
Clean the engine compartment before starting service works.
Page 224 of 715

03-20
Water
separator
(2) Di engine and its expected problems and remedies can be caused by
water in fuel
System supplement against paraffin separation ▶
In case of Diesel fuel, paraffin, one of the elements, can be separated from fuel during winter and
then can stick on the fuel filter blocking fuel flow and causing difficult starting finally. Oil
companies supply summer fuel and winter fuel by differentiating mixing ratio of kerosene and
other elements by region and season. However, above phenomenon can be happened if stations
have poor facilities or sell improper fuel for the season. In case of DI engine, purity of fuel is very
important factor to keep internal preciseness of HP pump and injector.
Accordingly, more dense mesh than conventional fuel filter is used. To prevent fuel filter internal
clogging due to paraffin separation, SYMC is using fuel line that high pressure and temperature
fuel injected by injector returns through fuel filter to have an effect of built-in heater (see fuel
system).
System supplement and remedy against water in fuel ▶
As mentioned above, some gas stations supply fuel with excessive than specified water. In the
conventional IDI engine, excessive water in the fuel only causes dropping engine power or engine
hunting. However, fuel system in the DI engine consists of precise components so water in the
fuel can cause malfunctions of HP pump due to poor lubrication of pump caused by poor coating
film during high speed pumping and bacterization (under long period parking). To prevent
problems can be caused by excessive water in fuel, water separator is installed inside of fuel
filter. When fuel is passing filter, water that has relatively bigger specific gravity is accumulated on
the bottom of the filter.
Water drain from water separator ▶
If water in the separator on the fuel filter exceeds a certain level, it will be supplied to HP pump
with fuel, so the engine ECU turns on warning lamp on the meter cluster and buzzer if water level
is higher than a certain level.
Due to engine layout, a customer cannot easily drain water from fuel filter directly, so if a
customer checks in to change engine oil, be sure to perform water drain from fuel filter.
To separate the water from the fuel filter,
remove the fuel filter assembly first.
Page 232 of 715

04-4
2. INSPECTION
1) Troubleshooting
When Abnormal Noises are Heard from the Engine Room ▶
For the vehicle equipped with DI engine, if a learning noise occurs in each range or other
noises occur, the major cause of it is a faulty turbocharger assembly. But an interference
issue, poor tightness or loose in the intake and exhaust system also can cause those noises.
This is mainly because the operator didn't follow the instruction exactly when reconnecting
the intake hoses and pipes which were disconnected to check the system or replace the air
cleaner. If the intake system is free of any faults, check the EGR and PCV oil separator
connected to the intake system.
The figure may be different from the actual engine. Therefore, read thoroughly below before
replacing the parts.
2) Abnormal Noise Caused by Poor Tightness of Intake System
When the DI engine is running, the air entered into the engine flows in the sequence as shown
above. If high intake pressure is applied to the loose or damaged part, a whistling noise may
occur, the intake air volume is measured incorrectly or the engine power is derated.
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04-51719-00
3) Troubleshooting Sequence
The basic checks for intake system are as follows:
Basic Checks for Intake System ▶
Make sure to replace or clean the air cleaner
element periodically. Otherwise, engine will be
derated or work abnormally because of low
intake air volume.
Unlike the fuel system, which is a closed
circuit, the intake system is an open circuit
system. Therefore any malfunction may occur
due to dust and dirt.
Most of the connections consist of hoses so
the system cannot withstand high temperature
and pressure. Also it can be deformed or
loosened easily because it is a clamp
mounting system. Thus, when checking the
engine, basic inspections, such as tightened
status check and visual inspection for hose,
etc., should be carried out in advance.
Other Checks for Intake System ▶
If the intake system is free of any faults,
check for EGR and PCV oil separator.
Page 245 of 715

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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06-51914-01
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 -
-
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. *
*
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. -
-
-
Page 247 of 715

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.