Page 947 of 6020

ENGINE COOLING 6B – 3
MAIN DATA AND SPECIFICATIONS
Description Item M/T A/T
Cooling system
W ater pump type
Pump to crankshaft speed ratio (To 1)
Delivery volume lit (US/UK gal)/min
Pump speed at 3000 rpm
W ater temperature at 30 °C (86 °F)
Pump bearing type
Thermostat type
Valve initial opening temperature °C ( °F)
(Oil cooler thermo valve)
(EGR cooler thermo valve)
Valve full opening temperature °C ( °F)
(Oil cooler thermo valve)
(EGR cooler thermo valve)
Valve lift at fully open position mm (in)
(Oil cooler thermo valve)
(EGR cooler thermo valve) Engine coolant forced circulation
Centrifugal impeller type 1.2
100 (26.3/22.2)
Double row shaft
W ax pellet with jiggle valve 82 (180)
76.5 (170) 40 (104)
95 (203)
90 (194)
55 (131)
9.5 (0.37)
4.5 (0.18)
3.5 (0.14)
Radiator Tube type corrugated
Heat radiation capacity 93.0 kW (79,980 kcal/h)
Heat radiation area 11.63 m2 (1.081ft2)
Radiator front area 0.28m2 (0.026 ft2)
Radiator dry weight 52 N (5.3 kg/11.7 lb) 53 N (5.4 kg/11.9 lb)
Radiator cap valve opening pressure 93.3 ~ 122.7 kPa (13.5 ~ 17.8 psi)
Engine coolant capacity 2.4 lit (5.1 U.S pint) 2.3 lit (4.9 U.S pint)
Engine coolant total capacity 10.1 lit (21.3 U.S pint) 10.0 lit (21.1 U.S pint)
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6B – 4 ENGINE COOLING
GENERAL DESCRIPTION
COOLANT FLOW
RTW 66ALF000101
The engine cooling system consists of the radiator, the water pump, the cooling fan, and the thermostat.
To quickly increase cold engine coolant temperature for smooth engine operation, the coolant is circulated by the
water pump and thermostat through the bypass hose and back to the cylinder body.
The coolant does not circulate through the radiator.
W hen the coolant temperature reaches specified value, the thermostat will begin to open and a gradually increasing
amount of coolant will circulate through the radiator.
The thermostat will be fully open when the coolant temperature reaches specified value. All of the coolant is now
circulating through the radiator for effective engine cooling.
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ENGINE COOLING 6B – 5
WATER PUMP
RTW 46ASF000101
A centrifugal type water pump forcefully circulates the coolant through the cooling system.
The water pump is not disassembled type.
THERMOSTAT
030RY00005
A wax pellet type thermostat is used.
The jiggle valve accelerates engine warm-up.
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Page 950 of 6020
6B – 6 ENGINE COOLING
110RS001
RADIATOR
The radiator is a tube type with corrugated fins. In order to
raise the boiling point of the coolant, the radiator is fitted with a
cap in which the valve is operated at 93.3
∼ 122.7 kPa (13.5 ∼
17.8 psi) pressure. (No oil cooler provided for M/T)
F06RW 005
Antifreeze Solution
NOTE: Antifreeze solution + W ater = Total cooling system
capacity.
Total Cooling System Capacity Lit (US / UK gal)
9.4 (2.5/21) 4JA1L/TC
M/T 10.1 (2.7/2.2) 4JH1TC
A/T 10.0 (2.6/2.2) 4JH1TC
See section 0B MAINTENACE AND LUBRICATION .
PTW 46BSH000201
NOTE:
To maintain the corrosion resistance of the aluminum
radiator, water and antifreeze must be combined in a 1:1
solution (50% antifreeze and 50% water)
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ENGINE COOLING 6B – 7
DIAGNOSIS
Engine Cooling Trouble
Symptom Possible Cause Action
Low Engine Coolant level Replenish
Thermo meter unit faulty Replace
Faulty thermostat Replace
Faulty Engine Coolant temperature
sensor Repair or replace
Clogged radiator
Clean or replace
Faulty radiator cap Replace
Low engine oil level or use of
improper engine oil Replenish or change oil
Clogged exhaust system
Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position
sensor circuit Repair or replace
Engine overheating
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Faulty thermostat Replace Engine slow to warm–up
Thermo unit faulty Replace
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Page 952 of 6020

6B – 8 ENGINE COOLING
Draining and Refilling Cooling System
Before draining the cooling system, inspect the system and
perform any necessary service to ensure that it is clean, does
not leak and is in proper working order. The engine coolant
(EC) level should be between the “MIN" and “MAX" lines o
f
reserve tank when the engine is cold. If low, check for leakage
and add EC up to the “MAX" line.
There should not be any excessive deposit of rust or scales
around the radiator cap or radiator filler hole, and the EC
should also be free from oil.
Replace the EC if excessively dirty.
P1010064
1. Completely drain the cooling system by opening the drain
plug at the bottom of the radiator.
2. Remove the radiator cap.
WARNING: To avoid the danger of being burned, do not
remove the cap while the engine and radiator are still hot.
Scalding fluid and steam can be blown out unde
r
pressure.
3. Disconnect all hoses from the EC reserve tank.
Scrub and clean the inside of the reserve tank with soap and water. Flush it well with clean water, then drain it.
Install the reserve tank and hoses.
4. Refill the cooling system with the EC using a solution that is at least 50 percent antifreeze.
Procedure for filling with coolant (in case of full change)
• Make sure that the engine is cool.
• Open radiator cap pour coolant up to filler neck.
• Pour coolant into reservoir tank up to “MAX" line.
• Tighten radiator cap and start the engine. After idling for 2
to 3 minutes, stop the engine and reopen radiator cap. If the
water level is lower, replenish.
WARNING: When the coolant is heated to a high
temperature, be sure not to loosen or remove the radiato
r
cap. Otherwise you might get scalded by not vapor or
boiling water. To open the radiator cap, put a piece of
thick cloth on the cap and loosen the cap slowly to reduce
the pressure when the coolant has become cooler.
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ENGINE COOLING 6B – 9
• After tightening radiator cap, warm up the engine at about
2000 rpm. Set heater adjustment to the highest temperature
position, and let the coolant circulate also into heater wate
r
system.
• Check to see the thermostat has opened through the
needle position of water thermometer, conduct a 5–minute
idling again and stop the engine.
• W hen the engine has been cooled, check filler neck fo
r
water level and replenish if required. Should extreme
shortage of coolant is found, check the cooling system and
reservoir tank hose for leakage.
• Pour coolant into the reservoir tank up to “MAX" line.
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6B – 10 ENGINE COOLING
WATER PUMP
REMOVAL AND INSTALLATION
Read this Section carefully before performing any removal and installation procedure. This Section gives you
important points as well as the order of operation. Be sure that you understand everything in this Section before you
begin.
Removal
1. Radiator Upper Hose 1) Partially drain the engine coolant.
2) Remove the radiator upper hose.
031R300003
2. Water Outlet Pipe
1) Disconnect the turbocharger-cooling pipe from outlet pipe.
2) Loosen the fixing bolt and remove the water outlet bolt.
3. Thermostat
Remove the thermostat from the thermostat housing.
Take care not to damage the thermostat.
4. Upper Fan Shroud
5. Fan and Fan Clutch 1) Loosen the fan clutch nuts.
2) Remove the fan together with the fan clutch. Take care not to damage the radiator core.
6. Fan Drive Belt and Pulley
1) Loosen the tension adjust bolt on the generator.
2) Remove the fan drive belt with the fan pulley.
030R300001 7. Water Pump
1) Remove the water pump bolts.
2) Remove the water pump.
030R300002
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