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01-8
4. CAUTION WHEN SERVICING THE ENGINE
1) Cleaness
Engine has a lot of precisely machined (grinding, polishing, lapping) surfaces. Thus, there should
be great cautions for cleaness when servicing the engine components. Apply the engine oil on the
sliding surfaces when assemblying the components. Every component should be disassembled
and reassembled in accordance with the correct sequences. Before servicing the engine, the
negative cable should be diconnected from the battery. Otherwise, some electric or electronic
components could be damaged.
2) Servicing
(1) Lifting up the vehicle
Always keep the safety precautions.
To prevent the vehicle from rolling down, put the chocks under the tires (when using a 4-post
lift).
Make sure to support the correct lifting points (when using a 2-post lift) -
-
-
(2) Exhaust system
Wear the safety glove when removing the exhaust pipe.
Make sure that the exhaust pipe is cooled before removing it. -
-Before service work, be sure to disconnect battery negative (-) terminal to prevent damages
by bad wire and short.
To prevent the foreign material from getting into engine cylinder, cover the inlet of air cleaner
if the air cleaner has been removed -
-
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01-90000-00
(3) Cautions before service
Prolonged exposure to the engine oil make cause a skin cancer or an irritation.
Used engine cotains the hazardous material that may cause the skin cancer. Do not allow the
used engine to make contact with your skin.
Make sure to wear the protection gloves and goggle when handling the engine oil. If contact
happens, rinse affected areas immediately with plenty of water. Do not wash it with gasoline or
solvent. If irritation persists, consult a doctor.
Improperly disposed engine oil can pollute the environment. Dispose used engine oil in
accordance with local environmental regulations. -
-
-
(5) Tightening the fastener
If fine dust or foreign material enters into DI engine's fuel system, there can be serious
damages between HP pump and injectors. So, be sure to cover removed fuel system
components with cap and protect removed parts not to be contaminated with dirt. (Refer to
cleanness in this manual while working on DI engine fuel system)
When working on the fuel line between priming pump and injector (including return line),
always plug the openings with caps to prevent foreign materials or dust from entering to the
openings and connections.
The HP fuel supply pipe (HP pump to fuel rail) and HP fuel pipe (Fuel rail to injector)
should be replaced with new ones when removed. 1.
2.
3. Scalding hot coolant and steam could be blown out under pressure, which could cause serious
injury. Never remove the coolant reservoir cap when the engine and radiator are hot.
(4) Lubrication system
3) Fuel and Oil System
If work on the fluid system such as fuel and oil, working area should be well ventilated and
smoking should be prohibited.
Gasket or seal on the fuel/lubrication system should be replaced with new ones and bolts and
nuts should be tightened as specified. -
-Clean the mating surfaces before tightening.
Place the marks with paint to tighten by angle if the angle wrench is not available. -
-
Page 133 of 828
01-12
1. SPECIAL SERVICE TOOLS
Name & Part number Tool How to use (on vehicle)
Part number: T99410010A
Name: Belt tension adjuster
Use to release tension
without removing belt when
replacing pulley or pump.
How to use (on engine)
Part number: T9941 0010A
Name: Flywheel fixing device
Use to fix flywheel or drive
shaft to prevent engine from
rotating when removing
crankshaft pulley
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02-110000-00
4. GUIDELINES ON ENGINE SERVICE
To prevent personal injuries and vehicle damages that can be caused by mistakes during engine
and unit inspection/repair and to secure optimum engine performance and safety after service
works, basic cautions and service work guidelines that can be easily forgotten during engine
service works are described in.
Cautions before service works
For safe and correct works, you must observe the working procedures and instructions in this
manual. And, use the designated tools as follow:
Engine stand / Heavy duty engine jack
To prevent the engine from starting abruptly, do not allow anybody to get in the vehicle while
servicing in engine compartment.
Before work on engine and each electrical equipment, be sure to disconnect battery negative
(-) terminal.
Before service works, be sure to prepare the works by cleaning and aligning work areas.
Do not allow the foreign material get into the fuel injection system.
When removing the engine, use only the safety hook on engine and engine hanger. Do not
support the bottom of oil pan with a jack.
Engine and accessories ▶
-
-
-
-
-
-
▶
Completely drain the engine oil, coolant and fuel from engine before removal.
Before disassembling/assembling the engine components, carefully read the working
procedures in this manual.
Make sure to keep the specified tightening torques during installation.
Clean and properly lubricate the parts before reassembly.
Carefully check that there are not any interference while servicing. -
-
-
-
-
Page 187 of 828
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 202 of 828

03-192210-01
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 1,800 bar.
<007a00960094008c0047008a00960094009700960095008c0095009b009a0047009000950047009000950091008c008a009b00960099004700880095008b0047006f007700470097009c00940097004700880099008c004700940088008a008f0090009500
8c008b00470088009b0047009b008f008c004700940090008a>rometer 100 μm of
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 210 of 828
04-31719-00
1. SPECIFICATION
Shorten the service interval under severe conditions such as driving on a dusty road or offroad. *
Unit Description Specification
Air cleaner elementFilter type Dry, filter element
Initial resistance Max. 300 mmAq
Service interval EU; Clean or change every 20,000 km
GEN: Clean or change every 15,000 km
Air cleaner assemblyWeight 103.9 kg
Operating temperature-30 ~ 100˚C
IntercoolerCore material Aluminum
Size 614W x 192H x 30T
Core size 614W x 192H x 30T
Tank material Plastic (Molding)
Efficiency 80%
Page 243 of 828

07-31543-00
1. SPECIFICATION
The engine oil filter element should be changed at the same time with the engine oil.
Regularly check the engine oil level and add the engine oil if necessary.
Remember to check the engine oil level and shorten the cycle to replace the engine oil
under severe driving conditions. -
-
Severe Driving Condition
Frequent stop-and-go traffic, extended idling, short driving distance below 6 km, driving
distance below 16 km when the outside temperature remains below freezing
Driving in a hilly or mountainous terrain, sandy, or dusty area
High load driving such as trailer towing
Taxi, patrol service or delivery service (extended idling and excessive driving with low
speed) -
-
-
-
Unit Specification
Oil pump Lubrication system Gear pump, forced circulation
Type Inscribed gear
Capacity 63 L at 4,000 rpm
Relief pressure5.8 bar ± 0.3 bar
Oil filter Type Full flow/Paper element
Engine oil Specified oil SAE 5W30 (approved by MB SHEET 229.51)
Capacity (L) Min.: 4.5 L
Max.: 6.0 L
Service interval Change every 15,000 km or 12 months (But,
shorten the service interval under severe
condition)
Oil injection
nozzleType Piston
Operating pressure 1.5bar
Closing pressure 1.0bar
Oil flow 4 L/min
Permissible pressure 10bar
Unit Specification
Oil pump Lubrication system Gear pump, forced circulation
Type Inscribed gear
Capacity 63 L at 4,000 rpm
Relief pressure5.8 bar ± 0.3 bar
Oil filter Type Full flow/Paper element
Engine oil Specified oil SAE 5W30 (approved by MB SHEET 229.51)
Capacity (L) Min.: 4.5 L
Max.: 6.0 L
Service
intervalEU Change every 20,000 km or 12 months
(The service interval should be shortened under
severe conditions)
General Change every 15,000 km or 12 months
(The service interval should be shortened under
severe conditions)
Oil pressure
switch