Page 105 of 1082

01-90000-00
5) Guidelines on Engine Service
(1) Cautions before service works
Make sure to disconnect the negative (-) cable from the battery to prevent any damage to electric
systems.
Make sure to clean the working area and to prepare the necessary tools before service works.
Always place the ignition switch to OFF position if not required. Otherwise, there could be
unexpected damage to electric devices or personal injuries due to short-circuit.
To prevent the foreign material from entering into the fuel injection system, completely seal the inlets
of HP pump, fuel hoses and high pressure pipes.
To remoev the engine, use the dedicated equipments such as engine jack, transmission jack, engine
stand and engine crane. -
-
-
-
-
(2) Engine and accessories
When disassembling the engine, related parts (bolts, gaskets, etc.) should be stored as a set.
Clean the components completely with engine oil before assembling if needed.
Fully drain the engine oil, coolant and fuel from the vehicle and seal the inlets with the plugs before
removing the engine.
All the interference should be eliminated before removing the engine. -
-
-
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(3) Electric devices
To prevent any damage to electric systems, make sure to disconnect the negative (-) cable from the
battery and place the ignition switch to OFF position before servicing.
Use only the specified parts with same ratings when replacing the electric devices. Check the
grounds and connections for looseness. -
- To prevent the personal injuries and vehicle damages that can be caused by mistakes during service
and to provide the optimized performance and safety after service works, the service technicials must
keep the basic cautions and service guidelines below. These could be easily forgotten during service
works.
Engine has a lot of precise components. The specified tightening torque and correct procedures should
be kept during service works. And, the working area is always clean and well prepared.
Extraordinary care should be taken when servicing the electric systems. Currently, the engine uses a lot
of electric devices. Short circuit and poor contact may cause the low engine performance, incomplete
combustion and other abnormalities.
Page 112 of 1082
02-50000-00
품명 규격 볼트
수량규정토오크(Nm) 비고
(총 토오크)
Knock sensorM8×28220 ± 5Nm-
Cam position sensorM8×141 10 ~ 14Nm -
T-MAP pressure sensor
M6×201
10 ± 1Nm-
Exhaust manifold M8 1040 ± 4Nm-
Turbocharger M8 325 ± 2.5Nm-
T/C support bracket bolt
125 ± 2.5Nm-
T/C support bracket bolt
M8 125 ± 2.5Nm-
T/C oil supply pipeM6(block side) 110 ± 1.0Nm-
M6(turbo side) 117 ± 2.0Nm-
T/C oil return pipeM6×16
(turbo side)210 ± 1Nm-
M6×16
(block side)210 ± 1Nm-
EGR valveM8×22325 ± 2.5Nm-
EGR pipe bolt (Intake
side)M6×25210 ± 1Nm-
EGR pipe bolt (EGR
cooler side)M8×16225 ± 2.5Nm-
Component Size
QuantityTightening torque
(Nm)Remark
(Total torque)
Hot water inlet pipeM6×12210 ± 1Nm-
AlternatorM10×90125 ± 2.5NmLower
M10×116146 ± 4.6NmUpper
A/C compressorM8×85425 ± 2.5Nm-
A/C bracketM6×25410 ± 1Nm-
Intake manifoldM8×35225 ± 2.5Nm-
M8×110625 ± 2.5Nm-
Oil filter moduleM8×40625 ± 2.5Nm-
M8×20125 ± 2.5Nm-
M8×140225 ± 2.5Nm-
Page 113 of 1082
02-6
품명 규격 볼트
수량규정토오크(Nm) 비고
(총 토오크)
Oil gauge tubeM6×16110 ± 1Nm-
Oil filter cap 125 ± 2.5Nm-
Fuel railM8×35225 ± 2.5Nm-
Injector clamp boltM6×6029 ± 1.0Nm
130˚ + 10˚-
High pressure pipe
(between HP pump and
fuel rail)M17 130 ± 3Nm
-
High pressure pipe
(between fuel rail and
injector)M17 430 ± 3Nm
-
Crank position sensor
M5×1418 ± 0.4Nm
-
Main wiringM6×16510 ± 1Nm-
Intake duct M8x25 325 ± 2.5Nm-
Power steering pumpM8×100325 ± 2.5Nm-
Mass balance shaft
(MBU)M8×45630 ± 3Nm-
Cylinder head front cove
rM6×10510 ± 1Nm-
품명 규격볼트
수량규정토오크(Nm)비고
(총 토오크)
Timing gear case coverM6×40710 ± 1Nm-
M6×45110 ± 1Nm-
M6×50310 ± 1Nm-
Cylinder head coverM6×352110 ± 1Nm-
Component Size
QuantityTightening torque
(Nm)Remark
(Total torque)
Idle pulley/Tensioner
pulley145 ± 4.5Nm
-
Glow plug M5 420 ± 2Nm-
Vacuum pumpM8×25310 ± 1Nm-
Page 118 of 1082

02-110000-00
3. CHECK AND INSPECTION
1) Cylinder
(1) Compression pressure test
Specified value ▶
Compression ratio
16.5 : 1
Test conditionat normal operating temperature (80˚C)
Compression pressureStandard32 bar
Minimum18 bar
Differential limit between cylindersMaximum 3 bar
The compression pressure test is to check the conditions of internal components (piston, piston ring,
intake and exhaust vale, cylinder head gasket). This test provides current engine operating status.
Before cranking the engine, make sure that the test wiring, tools and persons are keeping away from
moving components of engine (e.g., belt and cooling fan).
Park the vehicle on the level ground and apply the parking brake.
Do not allow anybody to be in front of the vehicle. -
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(2) Cylinder pressure leakage test
If the measured value of the compression pressure test is not within the specifications, perform the
cylinder pressure leakage test.Specified value ▶
Perform this test in the sequence of firing order.
Do not test the cylinder pressure leakage with wet type test procedure. (do not
inject the engine oil into the combustion chamber) -
-
Test condition: normal engine operating
temperature (80˚C)Specified value
Whole engine below 25%
at valve and cylinder head gasket below 10%
at piston ring below 20%
Page 124 of 1082
02-170000-00
EGR cooler bypass valve
Exhaust gas goes to combustion
chamber without through EGR
cooler in engine cooled, and the
valve is closed by vacuum
pressure.
2. VACUUM PUMP
Vacuum pump generates the vacuum pressure and supplies it to EGR cooler bypass solenoid. This
pump is single vane type and displacement is 210 cc/rev. The lubrication oil is supplied through the hole
in hollow shaft.
Components ▶
Vacuum pump
Pump capacity: 210 cc/rev
Speed: 375 to 3,000 rpm
Lubrication temperature:
-40 to 155°C
Oil: 5W30
Drive type: Driven by exhaust
Camshaft sprocketBrake booster
Page 130 of 1082

02-230000-00
Chain upper bush
Chain type: single bush
Chains: 112 EA
Tensioner rail
Installed between exhaust
Camshaft sprocket and
crankshaft sprocket
Hydraulic tensioner
Contains tensioner housing
plug, spring and check valve,
and operated by hydraulic
pressure
Crankshaft sprocket
Teeth: 21 EA
Exhaust Camshaft sprocket
Teeth: 42 EA
Clamping rail
Installed between exhaust
Camshaft sprocket and
crankshaft sprocket
7. CHAIN AND GEAR DRIVE SYSTEM
D20DTF engine uses single stage chain drive system. Timing chain drives the exhaust side and gear drive
the intake side. Timing chain is single bush type. Upper chain drives HP pump connected to intake
Camshaft by driving exhaust cam shift sprocke, and lower chain drives oil pump to lubricate the engine.
And, MBU (Mass Balance shaft Unit) drive gear drives MBU.
Components ▶
Chain lower bush
Chain type: single bush
Chains: 60 EAOil pump sprocket
Teeth: 20 EA
Mechanical type tensioner
Operated by internal spring
The timing links (gold color) on the timing chain are aligned with the timing marks on the
crankshaft sprocket and the camshaft sprocket whenever the crankshaft rotates 8 turns.
Page 139 of 1082
03-4
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.
Tool kit for high pressure lineTook kit for low pressure line
Page 157 of 1082

03-22
(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.
Water separator