Page 16 of 800
GENERAL INFORMATION
ENGINE COOLING14-2
GENERAL INFORMATION
M1141000100371
The cooling system is designed to keep every part of
the engine at appropriate temperature in whatever
condition the engine may be operated. The cooling
method is of the water-cooled, pressure forced circu
-
lation type in which the water pump pressurizes cool-
ant and circulates it throughout the engine. If the
coolant temperature exceeds the prescribed temper
-
ature, the thermostat opens to circulate the coolant
through the radiator as well so that the heat
absorbed by the coolant may be radiated into the air.
The water pump is of the centrifugal type and is
driven by the alternator drive belt from the crank
-
shaft. The radiator is the corrugated fin, down flow
type.
ItemSpecification
RadiatorPerformance kJ/h4G13Standard vehicles137,720
Vehicles with capacity up radiator
(option)161,288
4G18Standard vehicles161,288
Vehicles with capacity up radiator
(option)181,800
4G63181,800
A/T oil coolerPerformance kJ/h5,651
SERVICE SPECIFICATIONS
M1141000300687
ItemStandard valueLimit
Fan controller VA/C OFF1 or less-
A/C ONRepeat
8.2 ± 0.7
System voltage ± 2.6
-
High-pressure valve opening pressure of radiator cap kPa93 − 123Minimum 83
Range of coolant antifreeze concentration of radiator %30 − 60-
ThermostatValve opening temperature of
thermostat
°C
4G188 ± 1.5-
4G682 ± 1.5-
Full-opening temperature of
thermostat
°C
4G1100-
4G695-
Valve lift mm8.5 or more-
Page 35 of 800
ON-VEHICLE SERVICE
ENGINE COOLING14-21
ON-VEHICLE SERVICE
ENGINE COOLANT LEAK CHECKM1141001000300
WARNING
When pressure testing the cooling system,
slowly release cooling system pressure to
avoid getting burned by hot coolant.
CAUTION
•Be sure to completely clean away any mois-
ture from the places checked.
•When the tester is taken out, be careful not to
spill any coolant.
•
ACX01844
Cap adapter
Adapter
AC
Be careful when installing and removing the
tester and when testing not to deform the
filler neck of the radiator.
1. Check that the coolant leve l is up to the filler neck.
Install a radiator tester and apply 160 kPa
pressure, and then check for leakage from the
radiator hose or connections.
2. If there is leakage, repair or replace the
appropriate part.
RADIATOR CAP VALVE OPENING
PRESSURE CHECK
M1141001300389
NOTE: Be sure that the cap is clean before test-
ing. Rust or other foreign material on the cap seal
will cause an improper reading.
AC211643AB
Cap adapter
1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the gauge stops moving.
Minimum limit: 83 kPa
Standard value: 93 − 123 kPa
3. Replace the radiator cap if the reading does not remain at or above the limit.
ENGINE COOLANT REPLACEMENT
M1141001200434
WARNING
When removing the radiator cap, use care to
avoid contact with hot coolant or steam.
Place a shop towel over the cap and turn the
cap counterclockwise a little to let the pres
-
sure escape through the vinyl tube. After
relieving the steam pres sure, remove the cap
by slowly turning it counterclockwise.
1. Drain the water from the radiator, heater core and
engine after unplugging the radiator drain plug
and removing the radiator cap.
AC208283AC
Cylinder block
drain plug
<4G1>
Inlet side
AC303355
<4G6>
Inlet side
Cylinder block
drain plug
AB
2. Drain the water in the water jacket by unplugging the drain plug of the cylinder block.
3. Remove the radiator condenser tank and drain
the coolant.
4. Drain the coolant then clean the path of the coolant by injecting water into the radiator from
the radiator cap area.
Page 36 of 800
AC200625
Cylinder block
drain plug
AC
ON-VEHICLE SER VICE
ENGINE COOLING14-22
5.App l y the designa ted sealant to t he scre w area of
th e cylin der block drain plu g , and then tighten to
th e st and ard torq ue.
Sp e c ified s ealant: 3 M Nut Loc king Part
No. 4171 o r e quivale n t
Ti ghtenin g torque:
40 ± 5 N⋅m <4G1>
44 ± 5 N⋅m <4G6>
6.Securely tighten t he drain plug of t he radiator .
7.Reinst all the ra diato r con denser t ank.
CAUTION
Do not use alcohol or methanol anti-freeze or any
engine coolants mixed with alcohol or methanol
anti-freeze. The use of an improper anti-freeze
can cause corrosion of the aluminium compo
-
nents.
AC303612AB
MB991871
AIR HOSE
8. By referring to the section on coolant, select an
appropriate concentration for safe operating
temperature within the range of 30 to 60%. Use
special tool LLC changer (MB991871) to refill the
coolant. A convenient mixture is a 50% water and
50% antifreeze solution (freezing point:
−31°C).
Recommended antifreeze: DIAQUEEN SUPER LONG LIFE COOLANT or equivalent
Quantity:
5.0 L <4G1>
7.0 L <4G6>
NOTE: For how to use special tool MB991871,
refer to its manufacturer’s instructions.
9. Reinstall the radiator cap.
10.Start the engine and let it warm up until the thermostat opens.
11.After repeatedly revving the engine up to 3,000 r/min several times, then stop the engine.
12.Remove the radiator cap after the engine has become cold, and pour in coolant up to the brim.
Reinstall the cap.
CAUTION
Do not overfill the radiator condenser tank.
13.Add coolant to the radiator condenser tank between the "F" and "L" mark if necessary.
CONCENTRATION MEASUREMENT
M1141001100352
Measure the temperature and specific gravity of the
engine coolant to check the antifreeze concentration.
Standard value: 30 − 60% (allowable concentra-
tion range)
Recommended antifreeze: DIAQUEEN SUPER
LONG LIFE COOLANT or equivalent
CAUTION
If the concentration of the anti-freeze is below
30%, the anti-corrosion property will be
adversely affected. In addition, if the concentra
-
tion is above 60%, both the anti-freezing and
engine cooling properties will decrease, affecting
the engine adversely. For these reasons, be sure
to maintain the concentration level within the
specified range.
COOLING FAN MOTOR DRIVE CONTROL
UNIT CHECK
M1141006100250
1. Remove the cooling fan motor drive control unit connector.
AC103195
Y1716AU
1
23
AC
Cooling fan motor
drive control unit
2. Turn the ignition switch to the "ON" position, and
measure the voltage between terminal 1 and 3 at
the harness side connector.
Standard value: system voltage