1998 OPEL FRONTERA cooling

6B – 2 ENGINE COOLING
Legend
(1) Turbocharger
(2) Thermostat
(3) Reservoir Tank
(4) Radiator
(5) Bypass(6) Oil Cooler
(7) Cooling fan
(8) Water Pump
(9) Thermo Valve
(10) Car Heater
(11) EGR Cooler
GENERAL DESCRIPTION
COOLANT FLOW
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6
9
9
For Europe only
10
8
4
325
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11
032R200001
The cooling system is a pressurized coolant forced
circulation type which consists of water pump,
thermostat, cooling fan, radiator and other components. The circulating coolant cools the lubricating oil in the oil
cooler and turbocharger.

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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6B – 4 ENGINE COOLING
ANTI-FREEZE SOLUTION
Relation between Mixing ratio and Freezing point
Freezing temperature of the engine coolant varies
with the ratio of anti-freeze solution in water.
Proper mixing ratio can be determined by refering
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.
Calculation of mixing ratio
Mixing ratio (%)
=Anti-freeze solution (Lit/qt.)
100
Anti-freeze solution (Lit/qt.) + Water (Lit/qt.)
For example
In case total coolant capacity = 10

It is necessary to mix about 35% anti-freeze
solution at ambient temperature minus 20°C.
Capacity of anti-freeze solution:
35
10 = 3.5 100
Water capacity: 10
– 3.5 = 6.5 
Therefore, you prepare the water 6.5 and anti-
freeze solution 3.5
, then mix them to get total
10
coolant.
Mixing ratio
Check the specific gravity of engine coolant in the
cooling system in temperature ranges from 0° C to
50° C using a suction type hydrometer, then
determine the density of the coolant by referring to
the table at below.
-1010 0
Freezing Temperature(
C)
20 30 Antifreeze Solution Density(%)
40 50
-20
-30
-40
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1,100
20 10 30 4060%
50%
40%
20%
10%
30%
Antifreeze Solution Temperature(
C) 50 60 70 0
Specific Gravity
1,090
1,080
1,070
1,060
1,050
1,040
1,030
1,020
1,010
1,000
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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.

6B – 6 ENGINE COOLING
REMOVAL
1. Drain coolant.
2. AC Generator Drive Belt
1) Loosen AC Generator mounting bolt, adjust
plate lock bolt, and remove the drive belt.
3. Cooling Fan Assembly
1) Remove lock nut and take out cooling fan
assembly with cooling fan clutch.
4. Water Pump Assembly
INSPECTION
Make necessary repair and parts replacement if
excessive wear or damage is found during inspection.
Should any of the following problems occur, the entire
water pump assembly must be replaced.
1) Cracks in the water pump body
2) Coolant leakage from the seal unit
3) Excessive play in radial direction or abnormal noise
4) Excessive play in thrust direction
5) Cracks or corrosion in the impeller
INSTALLATION
1. Gasket
1) Set gasket to gear case.
2. Water Pump Assembly
1) Install water pump assembly, and tighten to
specified torque.Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
3. Cooling Fan Assembly
1) Install cooling fan assembly, and tighten to
specified torque.
Torque: 8 Nꞏm (0.8 kgꞏm/5.8 lb ft)
4. AC Generator Drive Belt
1) Install AC Generator drive belt and adjust belt
tension.
Torque: 40 Nꞏm (4.1 kgꞏm/29.7 lb ft)
For ACG to bracket
20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
For ACG to adjust plate
5. Fill coolant to specified capacity.
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Legend
(1) Fan Pulley
(2) Water Pump Assembly
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ON-VEHICLE SERVICE
WAT E R P U M P

ENGINE COOLING 6B – 7
THERMOSTAT
REMOVAL
1. Disconnect battery ground cable.
2. Drain coolant from the radiator and engine.
3. Thermostat housing
1) Remove mounting bolt and remove thermostat
housing together with radiator hose.
4. Gasket
5. Thermostat
INSPECTION
Make necessary repair and parts replacement if
excessive wear or damage is found during inspection.
Submerge the thermostat assembly in the water.
Place wooden blocks on the bottom of the water
container.
Do not heat the thermostat directly.
Gradually increase the water temperature. Stir the
water so that the entire water is the same temperature.
1) Make sure that valve begins to open at the
specified temperature.
Valve Opening Temperature: 85°C (185°F)
2) Make sure that valve opens fully at the specified
temperature.
Valve Full Open Temperature: 100°C (212°F)
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4
Legend
(1) Bolt
(2) Thermostat Housing
(3) Thermostat
(4) Intake Manifold
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6B – 8 ENGINE COOLING
INSTALLATION
1. Thermostat
1) The jiggle valve of the thermostat must face the
cylinder head side.
2. Gasket
3. Install thermostat housing and tighten bolt to the
specified torque.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
4. Reconnect water hose
1) Fill coolant to full level.
2) Reconnect battery ground cable.
5. Start the engine check for coolant leakage.

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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