Page 1289 of 4264
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.
When 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.
Page 1295 of 4264
ENGINE COOLING 6B – 15
RADIATOR
REMOVAL AND INSTALLATION
Radiator and Associated Parts
RTW36BLF000101
Legend
1. Radiator Hose
2. Drain Plug
3. Fan Guide, Lower
4. Fan Guide
5. Bracket
6. Reserve Tank Hose
7. Reserve Tank
8. Radiator Cap
9. Radiator Assembly
Page 1297 of 4264

ENGINE COOLING 6B – 17
Inspection and Repair
Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is discovered
during inspection.
Radiator Cap
Measure the valve opening pressure of the pressurizing valve
with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside the
standard range.
Valve opening pressure kPa (psi) 93.3
122.7 (13.5
17.8)
Cap tester: 5–8840–0277–0
Adapter: 5–8840–2603–0
Check the condition of the vacuum valve in the center of the
valve seat side of the cap. If considerable rust or dirt is found,
or if the valve seat cannot be moved by hand, clean or replace
the cap.
110RS006
Valve opening vacuum kPa (psi) 1.96
4.91 (0.28
0.71)
Radiator Core
1. A bent fin may result in reduced ventilation and overheating
may occur. All bent fins must be straightened. Pay close
attention to the base of the fin when it is being straightened.
2. Remove all dust, bugs and other foreign material.
Flushing the Radiator
Thoroughly wash the inside of the radiator and the engine
coolant passages with cold water and mild detergent. Remove
all signs of scale and rust.
Cooling System Leakage Check
Use a radiator cap tester to force air into the radiator through
the filler neck at the specified pressure of 196 kPa (28.5 psi)
with a cap tester:
Leakage from the radiator
Leakage from the coolant pump
Leakage from the water hoses
Page 1835 of 4264

ENGINE MECHANICAL (6VE1 3.5L) 6A-11
Symptom Possible Cause Action
Engine overheating Level of Engine Coolant too low Replenish
Fan clutch defective Replace
Thermostat defective Replace
Engine Coolant pump defective Correct or replace
Radiator clogged Clean or replace
Radiator filler cap defective Replace
Level of oil in engine crankcase too
low or wrong engine oil Change or replenish
Resistance in exhaust system
increased Clean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrect Replace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shorted Correct or replace
Cylinder head gasket damaged Replace
Engine overcooling Thermostat defective Replace (Use a thermostat set to
open at 82C (180F))
Engine lacks compression ———— Refer to Hard Start
Others Tire inflation pressure abnormal Adjust to recommended pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level of oil in engine crankcase too
high Correct level of engine oil
EGR valve defective Replace
Page 1927 of 4264
ENGINE COOLING (6VE1 3.5L) 6B-3
Water Pump
The EC pump is a centrifugal impeller type and is driven
by a timing belt.
030RS001
Thermostat
The thermostat is a wax pellet type with a air hole(1)
and is installed in the thermostat housing.
031RW002
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)
110RS001
Antifreeze Solution
Calculating mixing ratio
F06RW005
Page 1928 of 4264
6B-4 ENGINE COOLING (6VE1 3.5L)
NOTE: Antifreeze solution + Water = Total cooling
system capacity.
Total Cooling System Capacity
M/T 12.3Lit (13.0Us qt)
A/T 12.2Lit (12.9Us qt)
See section 0B MAINTENACE AND LUBRICATION.
Mixing ratio
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).
RTW46BSH000201
Page 1929 of 4264
ENGINE COOLING (6VE1 3.5L) 6B-5
Diagnosis
Engine Cooling Trouble
Symptom Possible Cause Action
Engine overheating 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
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Engine slow to warm–up Faulty thermostat Replace
Thermo unit faulty Replace
Page 1930 of 4264

6B-6 ENGINE COOLING (6VE1 3.5L)
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 of 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 o
r
scales around the radiator cap or radiator filler hole, and
the EC should also be free from oil.
Replace the EC if excessively dirty.
1. Completely drain the cooling system by opening the
drain plug at the bottom of the radiator.
P1010064
2. Remove the radiator cap.
WARNING: To avoid the danger of being burned, do
not remove the cap while the engine and radiato
r
are still hot. Scalding fluid and steam can be blown
out under 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 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. Afte
r
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
radiator cap. Otherwise you might get scalded by
not vapor or boiling water. To open the radiato
r
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.
After tightening radiator cap, warm up the engine at
about 2000 rpm. Set heater adjustment to the
highest temperature position, and let the coolan
t
circulate also into heater water 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.
When the engine has been cooled, check filler neck
for 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.