radiator cap OPEL FRONTERA 1998 User Guide

ENGINE MECHANICAL 6A – 11
Remove the radiator filler cap only when absolutely
necessary.
Always check the coolant level when the engine is cold.
Always refer to the chart at the left to determine the
correct cooling water to antifreeze solution mixing ratio.
Cooling System Inspection
Install a radiator filler cap tester to the radiator. Apply
testing pressure to the cooling system to check for
leakage.
The testing pressure must not exceed the specified
pressure.
Testing Pressure: 196 kPa (2 kg/cm
2/28.45 psi)
Radiator Cap Inspection
The radiator filler cap is designed to maintain coolant
pressure in the cooling system at 103 kPa (1.05
kg/cm
2/15 psi).
Check the radiator filler cap with a radiator filler cap
tester.The radiator filler cap must be replaced if it fails to hold
the specified pressure during the test procedure.
Radiator Filler Cap Pressure Valve: 88.2 – 117.6 kPa
(0.899 – 1.199 kg/cm
2/12.8 – 17.1 psi)
Negative Valve (Reference): 1.0 – 3.9 kPa
(0.01 – 0.04 kg/cm
2/0.14 – 0.57 psi)
Thermostat Operating Test
1. Completely submerge the thermostat in water.
2. Heat the water.
Stir the water constantly to avoid direct heat being
applied to the thermostat.
3. Check the thermostat initial opening temperature.
Thermostat Initial Opening Temperature:
83 – 87°C (181 – 189°F)
4. Check the thermostat full opening temperature.
Thermostat Full Opening Temperature:
100°C (212°F)
Valve Lift at Fully Open Position: 9.5 mm (0.374
in)0
-10
-20
-30
-40
-50
-60
10 20 30
Mixing ratio (%)
Freezing point (
C)
40 50 60
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ENGINE COOLING 6B – 3
WAT E R P U M P
The coolant pump is a centrifugal impeller type and is
driven by V type drive belt.
Legend
(1) Roller Bearing
(2) Ball Bearing
(3) Seal Unit
THERMOSTAT
The thermostat is a wax pellet type with a jiggle valve
and is installed in the thermostat housing.
Legend
(1) Bolt
(2) Thermostat Housing
(3) Thermostat
(4) Intake Manifold
RADIATOR
The radiator is a tube type with corrugated fins. In order
to raise the boiling point of coolant, the radiator is fitted
with a cap in which the valve is operated under the
pressure.
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ENGINE COOLING 6B – 5
ENGINE COOLANT CHANGE
PROCEDURE
1. To change engine coolant, make sure that the
engine is cool.
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 hot 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 once the coolant has
become cooler.
2. Open radiator cap and drain the cooling system by
loosening the drain valve on the radiator and on the
cylinder body.
NOTE: For best results it is suggested that the engine
cooling system be flushed at least once a year. It is
advisable to flush the interior of the cooling system
including the radiator before using anti-freeze
(ethylene-glycol based).
Replace damaged rubber hoses as the engine anti-
freeze coolant is liable to leak out even minor cracks.
Isuzu recommends using Isuzu genuine anti-freeze
(ethylene-glycol based) or equivalent, for the cooling
system and not add any inhibitors or additives.
CAUTION:
A failure to correctly fill the engine cooling system
in changing or topping off coolant may sometimes
cause the coolant to overflow from the filler neck
even before the engine and radiator are completely
full.
If the engine runs under this condition, shortage of
coolant may possibly result in engine overheating.
To avoid such trouble, the following precautions
should be taken in filling the system.
3. To refill engine coolant, pour coolant up to filler neck
using a filling hose which is smaller in outside
diameter than the filler neck. Otherwise air between
the filler neck and the filling hose will block entry,
preventing the system from completely filling up.
4. Keep a filling rate of 9 liter/min. or less. Filling over
this maximum rate may force air inside the engine
and radiator.
And also, the coolant overflow will increase, making
it difficult to determine whether or not the system is
completely full.
5. After filling the system full, pull out the filling hose
and check to see if air trapped in the system is
dislodged and the coolant level goes down. Should
the coolant level go down, repeat topping-off until
there is no more drop in the coolant level.
6. Directly after filling the radiator, fill the reservoir to
the maximum level.
7. Install and 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 radiator cap.
Otherwise you might get scalded by hot 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 once the coolant has
become cooler.
8. After tightening radiator cap, warm up the engine at
about 2,000 rpm.
Set heater adjustment to the highest temperature
position, and let the coolant circulate also into
heater water system.
9. Check to see the thermostat has opened by the
needle position of a water thermometer, conduct a
5-minute idle again and stop the engine.
10. When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant be found, check the
coolant system and reservoir tank hose for leakage.
11. Fill the coolant into the reservoir tank up to “MAX”
line.

ENGINE COOLING 6B – 9
RADIATOR
REMOVAL
1. Disconnect battery ground cable
2. Loosen drain plug to drain coolant.
3. Radiator Hose
1) Disconnect lower hose and upper hose from the
engine.
4. Fan Guide
1) Remove clips on both sides and the bottom lock.
5. Reservoir Tank Hose
1) Disconnect the hose from radiator.
6. Bracket
7. Radiator Assembly
1) Remove the radiator assembly upward by the
hoses taking care not to damage the radiator
core by the fan blade.
2) Remove rubber cushions on both sides of the
bottom.
INSPECTION
Radiator Cap
1) Measure the valve opening pressure with the
radiator cap tester. Replace the radiator cap if it
exceeds the standard.
Valve opening pressure: 93.2 – 122.7 kPa
(0.95 – 1.25 kg/cm
2/
13.5 – 17.8 psi)
Check the condition of the negative pressure valve in
the center of the valve seat side of the cap. If the valve
seat does not move smoothly due to rust or dust, clean
and replace the radiator cap.Radiator Core
1) Deformed radiator fins could reduce radiation
effects, resulting in overheating. Straighten the fins.
In such a case, take care not to damage the fin
roots.
2) Remove dust and other foreign materials.
Flushing the Radiator
1) Wash the inside of radiator and the coolant
passage with water and a neutral detergent.
Remove all scales and rust.
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6B – 10 ENGINE COOLING
Checking for Coolant Leakage
1) Check the cooling system for leakage with the
radiator cap tester by applying 196.0 kPa (28.4 psi)
air pressure from filler neck to inside the radiator.
INSTALLATION
1. Radiator Assembly
1) Install rubber cushions on both sides of radiator
bottom.
2) Install radiator assembly with hose, taking care
not to damage the radiator core by a fan blade.
2. Bracket
1) Support the radiator upper tank with the bracket
and fix the radiator.
3. Reserve Tank Hose
4. Fan Guide, Lower
5. Radiator Hose
1) Connect inlet hose and outlet hose to the
engine.
2) Connect battery ground cable.
3) Pour coolant up to filler neck of radiator, and up
to MAX mark of reserve tank.
4) Start engine to warm up, and check for coolant
level. Replenish coolant if it does not reach the
radiator filler neck, and tighten the cap
completely.
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6A–11
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine overheatingLevel of Engine Coolant too lowReplenish
Fan clutch defectiveReplace
Incorrect fan installedReplace
Thermostat defectiveReplace
Engine Coolant pump defectiveCorrect or replace
Radiator cloggedClean or replace
Radiator filler cap defectiveReplace
Level of oil in engine crankcase too
low or wrong engine oilChange or replenish
Resistance in exhaust system
increasedClean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrectReplace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shortedCorrect or replace
Cylinder head gasket damagedReplace
Engine overcoolingThermostat defectiveReplace (Use a thermostat set to
open at 82
C (180F))
Engine lacks compression————Refer to Hard Start
OthersTire inflation pressure abnormalAdjust to recommended pressures
Brake dragAdjust
Clutch slippingAdjust or replace
Level of oil in engine crankcase too
highCorrect level of engine oil
Exhaust Gas Recirculation Valve
defectiveReplace
Engine Noisy
Abnormal engine noise often consists of various noises
originating in rotating parts, sliding parts and othermoving parts of the engine. It is, therefore, advisable to
locate the source of noise systematically.
Condition
Possible causeCorrection
Noise from crank journals or from
crank bearings
(Faulty crank journals and crankOil clearance increased due to worn
crank journals or crank bearingsReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
yj
bearings usually make dull noise that
becomes more evident when
accelerating)Crankshaft out of roundReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
Crank bearing seizedCrank bearing seized. Replace crank
bearings and crankshaft or regrind
crankshaft and install the undersize
bearing
Troubleshooting Procedure
Short out each spark plug in sequence using insulated
spark plug wire removers. Locate cylinder with defectivebearing by listening for abnormal noise that stops when
spark plug is shorted out.

ENGINE COOLING6B–3
Thermostat
The thermostat is a wax pellet type with a air hole(1) and is
installed in the thermostat housing.
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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 88.2
117.6
kPa (12.8
1 7 . 0 p s i ) p r e s s u r e . ( N o o i l c o o l e r p r o v i d e d f o r
M/T)
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Anti Freeze Solution
Relation between the mixing ratio and freezing
temperature of the EC varies with the ratio of
anti–freeze solution in water. Proper mixing ratio can
be determined by referring to the chart. Supplemental
inhibitors or additives claiming to increase cooling
capability that have not been specifically approved by
Isuzu are not recommended for addition to the cooling
system.
Calculating mixing ratio
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ENGINE COOLING6B–5
Diagnosis
Engine Cooling Trouble
ConditionPossible causeCorrection
Engine overheatingLow Engine Coolant levelReplenish
Incorrect fan installedReplace
Thermo meter unit faultyReplace
Faulty thermostatReplace
Faulty Engine Coolant temperature
sensorRepair or replace
Clogged radiatorClean or replace
Faulty radiator capReplace
Low engine oil level or use of
improper engine oilReplenish or change oil
Clogged exhaust systemClean exhaust system or replace
faulty parts
Faulty Throttle Position sensorReplace throttle valve assembly
Open or shorted Throttle Position
sensor circuitRepair or replace
Damaged cylinder head gasketReplace
Engine overcoolingFaulty thermostatReplace
Engine slow to warm–upFaulty thermostatReplace
Thermo unit faultyReplace

6B–6
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 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 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.
1. Completely drain the cooling system by opening the
drain plug (2) at the bottom of the radiator.
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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
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 at least 50 percent antifreeze but no more than
70 percent antifreeze.
5. Fill the radiator to the base of the filler neck.
Fill the EC reserve tank to “MAX” line when the engine
is cold.
6. Block the drive wheels and firmly apply the parking
brake. Shift an automatic transmission to “P” (Park)
or a manual transmission to neutral.
7. Remove the radiator cap. Start the engine and warm
it up at 2,500
3,000 rpm for about 30 minutes.
8. When the air comes out from the radiator filler neck
and the EC level has gone down, replenish with the
EC. Repeat this procedure until the EC level does not
go down. Then stop the engine and install the radiator
cap. Let the engine cool down.9. After the engine has cooled, replenish with EC up to
the “MAX” line of the reserve tank.
10. Start the engine. With the engine running at 3,000
rpm, make sure there is no running water sound from
the heater core (behind the center console).
11. If the running water sound is heard, repeat steps 8 to
10.

6B–10
ENGINE COOLING
6. Disconnect the reserve tank hose(4) from radiator.
7. Remove bracket(5).
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8. Lift up and remove the radiator assembly with hose,
taking care not to damage the radiator core with a fan
blade.
9. Remove rubber cushions on both sides at the bottom.
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) 88.3
117.7
(12.8
17.1)
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.Valve opening vacuum kPa (psi) 1.96
4.91
(0.28
0.71)
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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
Check the rubber hoses for swelling.