Page 190 of 1336

0000-00
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. -
-
-
-
(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 202 of 1336
Oil gauge tube1-
Oil filter cap 1
-
Fuel rail
2-
Injector clamp bolt
2-
High pressure pipe
(between HP pump and
fuel rail)M17 1
-
High pressure pipe
(between fuel rail and
injector)M17 4
-
Crank position sensor
1-
Main wiring
5-
Intake duct M8x25 3
-
Power steering pump
3-
Mass balance shaft
(MBU)
6-
Cylinder head front cove
r5-
Timing gear case cover
7-
1-
3-
Cylinder head cover
21-
Component Size
QuantityTightening torque
(Nm)Remark
(Total torque)
Idle pulley/Tensioner
pulley1
-
Glow plug M5 4
-
Vacuum pump
3-
Page 227 of 1336
0000-00
1. SPECIFICATION
Description Specification
Fuel Diesel
Fuel filterTypeFuel heater + priming pump + water separator
integrated type
Filter type Changeable filter element type
every 40,000 km
every 45,000 km
Water accumulating capacity 200 cc
Heater capacity 250W 13.5V
Injector System pressure 1800 bar
High pressure fuel
pumpType Eccentric cam/Plunger type
Operating type Gear driven type
Normal operating temperature
Operating pressure 1800 bar
Operating temperature
Low pressure fuel
pumpType Vane type
Gear ratio (pump/engine) 0.5 : 1
Pressure 6 bar
Fuel tankCapacity 57 L
Material Plastic
Fuel sender Dual sender type
Change intervalEU
GEN
Page 229 of 1336
0000-00
3. 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 241 of 1336
0000-00
Static test for backleak of injector
Disconnect the injector return hose and cover
the openings with caps shaped screw (included
in the special tool). 1.
Connect the hose of the container for
measuring backleak to the return nipple of the
injector.
(prevent air entry to the low pressure line) 2.
Disconnect the IMV connector of the high
pressure pump and then fuel pressure
sensor connector. 3.
The connector of the injector can be easily
contaminated. Always keep it clean.
Crank the engine for 5 seconds.
Check the flow volume of injector backleak. 4.
5.
If the value is out of the specified range,
replace the injector.
Flow volume of injector
backleakbelow 20 cm
Page 244 of 1336
HP pump pressure test
Prepare a special tool for high pressure test
and clean it thoroughly to prevent foreign
materials from entering. 1.
Disconnect the high pressure fuel supply pipe
on the HP pump and install the close rail in the
tool kit. 2.
Connect the other end of the close rail to the
fuel rail for test 3.
Disconnect the return hose for HP pump and
connect the clear hose and connect its the
other end to the return port of the fuel rail for
test. 4.
Connect the digital tester connector to the
sensor connector of the fuel rail for test.
Crank the engine 2 times for 5 seconds after
removing the IMV connector and fuel rail
pressure sensor connector.
Read the pressure value displayed on the
tester display is within the specified range. 5.
6.
7.
Specification1,050 bar or more
Page 246 of 1336

2) Cleanness
(1) Cleanness of DI engine fuel system
Cleanness of DI engine fuel system and service procedures
The fuel system for DI engine consists of transfer (low pressure) line and high pressure line.
Its highest pressure reaches over 1,600 bar.
preciseness.
The pressure regulation and injector operation are done by electric source from engine ECU.
Accordingly, if the internal valve is stuck due to foreign materials, injector remains open.
Even in this case, the HP pump still operates to supply high pressurized fuel. This increases the
pressure to combustion chamber (over 250 bar) and may cause fatal damage to engine.
You can compare the thickness of injector nozzle hole and hair as shown in below figure (left side). The
below figure shows the clearance between internal operating elements.
The core elements of fuel system has very high preciseness that is easily affected by dust or very small
foreign material. Therefore, make sure to keep the preliminary works and job procedures in next pages.
If not, lots of system problems and claims may arise.
Hair
Nozzle holeValve actuator lift - 0.028 mm
Diameter
0.04 mm
Operating
clearance
0.002 mm
Diameter
2.0 mm
Page 247 of 1336

0000-00
(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