Page 171 of 796

02-12
5. 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. ▶
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Page 185 of 796
02-26
Location of Expansion Plugs
1) Cylinder Head
(1) Overview
The cylinder is made by gravity casting and the water jacket is integrated type.
The cylinder oil passage is drilled and sealed by cap.
The Camshaft bearing cap is also made by casting and installed on the cylinder head.
(2) Features
Front
Oil gallery expansion plug (M10)
Coolant expansion plug (M21)
Intake side
Rear
Page 209 of 796
02-50
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 223 of 796
03-16
Dynamic test for backleak of injector ▶
Warm up the engine so that the engine
coolant tem
perature be over 80℃ and star
the engine again.
Disconnect the injector return hose and cover
the openings with caps shaped screw
(included in the special tool). 1.
2.
Connect the hose of the container for
measuring backleak to the return nipple of
the injector.
Start the engine again and let the engine idle
for 30 seconds.
Perform backleak test of fuel system with a
diagnostic device after 30 seconds. 3.
4.
5.
This test consists of 4 cycles, and the engine rpm
reaches 3,500 rpm for 18 seconds in each cycle.
Check the amount of backleak collected into
the container and confirm that it is within the
specified range. 6.
Specification38 ml or less
Page 233 of 796

03-26
The engine ECU calculates the accelerator pedal based on the input signals from various sensors, and
controls the overall operation of the vehicle.
The ECU receives the signals from various sensor through data line, and performs effective air-fuel ratio
control based on these signals.
The crankshaft speed (position) sensor measures the engine speed, and the camshaft speed (position)
sensor determines the order of injections, and the ECU detects the amount of the accelerator pedal
depressed (driver's will) by receiving the electrical signals from the accelerator pedal sensor.
The mass air flow sensor detects the volume of intake air and sends the value to the ECU.
The major function of the ECU is controlling air-fuel ratio to reduce the emission level (EGR valve
control) by detecting instantaneous air flow change with the signals from the mass air flow sensor.
Also, the ECU uses the signals from the coolant temperature & air temperature sensors, booster
pressure sensor, atmospheric pressure sensor to: a) determine injection starting point and set value for
pilot injection, and b) deal with various operations and variable conditions.
Page 264 of 796
06-191914-01
2. COMPONENTS
Atmospheric pressure, RPM
signal * For details about control logic, refer to Chapter “Engine Control”.
E-VGT turbocharger
Improves engine powerAccelerator pedal position
sensor
Transfers driver's will to
accelerate to ECUEngine ECU (D20DTR)
E-VGT duty control
Coolant temperature sensor
Operates the VGT according to
engine warm-upT-MAP sensor
Improves the engine powerHFM sensor
Booster pressure and
temperature
Page 272 of 796
08-31520-00
1. SPECIFICATION
Description Specification
Cooling system Type Water cooling, forced circulation
Coolant Capacity approx. 11.5 L
RadiatorCore size589W x 538H x 27T (over 3,170 cm²)
Flow type Cross flow
AntifreezeType SYC1025 (Long life coolant)
Mixing ratio
(water:antifreeze)50 : 50
Cooling fan moduleMotor type DC motor
Motor weight 2.14 kg
Control type PWM type
Fan runout 3 mm
Coolant reservoirCapacity over 1.5 L
Circulation Closed roof type
Pressure cap Screw type
Pressure 1.4bar
ThermostatType Wax pallet type
Opening temperature90 ℃
Fully open temperature
100℃
Valve lift 8mm
Page 273 of 796

08-4
2. INSPECTION
Possible Cause Action
Coolant level
is
too low- Leak from the radiator
- Leak from the coolant auxiliary tank
- Leak from the heater core- Change the radiator
- Change the coolant auxiliary tank
- Change the heater
- Leak from the coolant hose
connections
- Damaged coolant hose - Reconnect the hose or replace
the clamp
- Change the hose
- Leak from the water pump gasket
- Leak from the water pump internal
seal- Change the gasket
- Change the water pump
- Leak from the water inlet cap
- Leak from the thermostat housing- Change the water inlet cap
gasket
- Change the thermostat sealing
- Incorrect tightening torque of the
cylinder head bolts
- Damaged cylinder head gasket- Tighten the bolts to the specified
torque
- Change the cylinder head gasket
Coolant
temperature is
too high- Coolant leakage (Coolant level is low)
- Improper coolant mixture ratio
- Kinked coolant hose- Add coolant
- Check the coolant concentration
(Anti-freeze)
- Repair or replace the hose
- Defective thermostat
- Defective water pump
- Defective radiator
- Defective coolant auxiliary tank or tank
cap- Change the thermostat
- Change the water pump
- Change the radiator
- Change the coolant auxiliary tank
or tank cap
- Cracks on the cylinder block or
cylinder head
- Clogged coolant passages in the
cylinder block or cylinder head- Change cylinder block or cylinder
head
- Clean the coolant passage
- Clogged radiator core - Clean the radiator core
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or
faulty wiring- Replace the sensor or repair the
related wiring
Coolant
temperature is
too low- Thermostat is stuck open - Change the thermostat
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or faulty
wiring- Replace the sensor or repair the
related wiring