Page 337 of 1082
01-130000-00
1. ENGINE COMPARTMENT
Coolant reservoir
OCV
Ignition coil
Rear oxygen sensor connector
Front oxygen sensor connector
Coolant temperature sensor
Purge control solenoid valve
Engine ECU
Battery
Fuse box 1.
2.
3.
4.
5.
6.
7.
8
9.
10.HECU assembly
Alternator
Fuel rail assembly
Injector
Intake manifold
Oil dipstick gauge
VIS solenoid valve
T-MAP sensor
Electronic throttle body
Air cleaner assembly 11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Page 346 of 1082
01-22
7. COOLING SYSTEM
Coolant reservoir
Water pump assembly
The water pump is driven by the engine drive belt and supplies
the coolant to each area of the engine.
Thermostat assembly
When the engine coolant
reaches 90˚C, the
thermostat starts to open (fully
open at 100˚C) and lets the
coolant flow to the radiator to
maintain the engine
temperature.
Page 353 of 1082

02-71116-01
Engine and accessories ▶
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.
When disassembling the engine, related parts (bolts, gaskets, etc.) should be stored as a set.
Carefully read the disassembly and reassembly procedures in this manual before starting the
works.
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. -
-
-
-
Tightening the fastener ▶
When reassembling the parts to G20DF, use the angle tightening as a final step.
1. Clean the mating surfaces before tightening.
2. Place the marks with paint to tighten by angle if the angle wrench is not available.Exhaust system ▶
Wear the protective gloves before removing the exhaust pipe.
The exhaust pipe is very hot immediately after stopping th engine. Check if the exhaust pipe is fully
cooled down before servicing the exhaust system. -
-
Cooling system ▶
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 the radiator are hot. -
The position and direction of the componets is based on the rear view.
Do not tighten the fasteners with excessive force. Especially, the threads of cylinder block could be
damaged.
The self screw bolt makes the thread itself when tightening it. Do not apply excessive force.
Do not reuse the bolt that has been tightened with angle tightening method.
Page 426 of 1082
08-32112-01
1. SPECIFICATION
Description Specification
Cooling system Type Water cooling, forced circulation
Coolant Capacity Approx. 8.0 ~ 8.5 L
RadiatorCore size 740W X 378.9H X 27T
Flow type Cross flow
AntifreezeType SYC 1025 (LLC)
Mixing ratio 50:50 (water:antifreeze)
Cooling fan moduleType Electric
Capacity 180 W + 120 W
Control type Series: low speed, Parallel: high speed
Coolant reservoirMin. capacity 1.6 L
Circulation Closed roof type
Pressure cap Screw type, 1.4 bar
ThermostatType Wax pallet type
Opening temperature90℃
Fully open temperature100℃
Valve lift 8mm
Page 429 of 1082
08-6
1) Coolant Level Check
Park the vehicle on level ground and apply the parking brake. Stop the engine and wait until it is
cooled down. The coolant level should be between the MAX and MIN mark on the coolant reservoir.
If the coolant level is below the “MIN” mark, immediately add coolant. A.
B.
Coolant reservoir
MAX
MIN
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.
Avoid any direct contact of the coolant to the painted body of the vehicle. -
-
Page 430 of 1082
08-72112-01
2) Leak Test
Release the pressure in the system by
loosening the pressure cap of the coolant
reservoir slightly. Then, remove the pressure
cap completely. A.
Never open the cap until the coolant
temperature becomes under 90℃ to
prevent any burn.
Add the coolant so that the coolant level is
between MAX and MIN mark on the coolant
auxiliary tank.
Connect the tester to the tank filler and apply
pressure (1.4 bar).
Check all the coolant hoses, pipes and
connections for leaks when the pressure of
the tester drops, and replace or tighten, if
necessary. B.
C.
D.
3) Thermostat
Immerse the thermostat into the water. Heat the
water and check the valve opening temperature.
Valve opening
temperature90±2℃
Page 431 of 1082

08-8
3. CAUTIONS
If 100% of anti-freeze is added, the water pump vane can be damaged and thermal conductivity can
be decreased resulting in poor circulation in the cooling system which leads to overheated engine.
Use of non-recommended coolant could cause damage to the cooling system and overheating of the
engine.
Opening the coolant reservoir cap while the engine is running or hot can cause burns by hot steam o
r
water.
To open the coolant reservoir cap, wrap the cap with a wet towel or thick cloth after the engine is
cooled down sufficiently.
If cool water is added to the heated engine, the engine or radiator can be deformed.
The anti-freeze in the coolant can damage the painted surface, so avoid the contact of the coolant to
the painted body.
The anti-freeze and water should be mixed in proper mixture ratio. Never add only water when
adding coolant.
If the anti-freeze content is too low, the coolant can be frozen while the engine can be overheated if
anti-freeze content is too high. -
-
-
-
-
-
-
-
Page 435 of 1082
08-12
Water pump
The water pump is driven by the engine drive belt and supplies
the coolant to each area of the engine.
Coolant reservoir
Thermostat
When the engine coolant
reaches 90℃, the thermostat
starts to open (fully open at
100℃) and lets the coolant
flow to the radiator to maintain
the engine temperature.
1. OVERVIEW
The coolant system is to keep the engine temperature stable.
2. COMPONENTS