SECTION 6B - ENGINE COOLING (X22SE 2.2L)

Service Precaution

General Description

Diagnosis

Draining and Refilling Cooling System

Water Pump

Water Pump and Associated Parts

Removal

Inspection

Installation

Thermostat

Removal

Inspection

Installation

Radiator

Radiator and Associated Parts

Removal

Inspection

Installation

Main Data and Specifications

Special Tool

Service Precaution

WARNING: THIS VEHICLE HAS A SUPPLEMENTAL

RESTRAINT SYSTEM (SRS). REFER TO THE SRS

COMPONENT AND WIRING LOCATION VIEW IN

ORDER TO DETERMINE WHETHER YOU ARE

PERFORMING SERVICE ON OR NEAR THE SRS

COMPONENTS OR THE SRS WIRING. WHEN YOU

ARE PERFORMING SERVICE ON OR NEAR THE

SRS COMPONENTS OR THE SRS WIRING, REFER

TO THE SRS SERVICE INFORMATION. FAILURE TO

FOLLOW WARNINGS COULD RESULT IN

POSSIBLE AIR BAG DEPLOYMENT, PERSONAL

INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM

REPAIRS.

CAUTION: Always use the correct fastener in the

proper location. When you replace a fastener, use

ONLY the exact part number for that application.

ISUZU will call out those fasteners that require a

replacement after removal. ISUZU will also call out

the fasteners that require thread lockers or thread

sealant. UNLESS OTHERWISE SPECIFIED, do not

use supplemental coatings (Paints, greases, or

other corrosion inhibitors) on threaded fasteners or

fastener joint interfaces. Generally, such coatings

adversely affect the fastener torque and the joint

clamping f or ce, and may dama ge the fastener . Wh en

you install fasteners, use the correct tightening

sequence and specifications. Following these

instructions can help you avoid damage to parts

and systems.

Techline

General Description

111RW001

Legend

EndOFCallout

The Cooling System is a pressurized type, where the

water pump, which is cambelt driven, forces the

circulation of the coolant through the cylinder bloc k and

head. The thermostat regulates the flow of coolant

between the radiator and the bypass circuit. The heater

is part of the bypass circuit. The throttle body pre–heat

is a separate circuit which is not regulated by the

thermostat. An oil cooler may be fitted as part of this

circuit.

Water Pump

The water pump is centrifugal type and is driven by

timing belt.

030RW003

(1) Water Pump

(2) Thermostat

(3) Radiator

(4) Reserve Tank

(5) Coolant Distributor

(6) Cy linde r Bl ock and Head

(7) Thrott le Bod y

(8) Heater

Thermostat

The thermostat is a bypass type and is a wax pellet type

with a air hole (1).

031RW003

Radiator

The radiator is a flow type with corrugated fins.

110RX005

Antifreeze Solutio n

• Relation between Mixing ratio and Freezing

temperature of the engine coolant varies with the

ratio of antifreeze 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

F06RW005

NO TE: Antifreeze solution + Water = Total cooling

system capacity.

Total Cooling System Capacity

7.2Lit (1.90US gal)

111RW002

• Mixing ratio

Check the specific gravity of engine coolant in the

cooling system temperature ranges from 0°Χ το 50°Χ

υσινγ α συχτιον type hydrometer, then determine the

density of the engine coolant by referring to the table.

Diagnosis

Engine Cooling Trouble

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 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 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.

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. Remov e 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.

Condition Possible cause Correction

Engine Cooling Trouble

Engine overheating Low Engine Coolant level Replenish

Thermo mater 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 cy li nde r hea d gasket Replac e

Engine overcooling Faulty thermostat Replace

Engine slow to warm–up Faulty thermostat Replace

Thermo unit faulty Replace

Water Pump

Water Pump and Associated Parts

030RW004

Legend

EndOFCallout

Removal

1.Disconnect battery ground cable.

2.Drain coolant.

3.Radiator hose (on inlet pipe side).

4.Remove timing belt, refer to “Timing Belt" in this

manual.

5.Remove water pump assembly.

Inspection

Make necessary repair and parts replacement if

extreme wear or damage is found during inspection.

Should any of the following problems occur, the entire

water pump assembly must be replaced:

•Crack in the water pump body

•Engine Coolant (EC) leakage from the seal unit

•Play or abnormal noise in the bearing

•Cracks or corrosion in the impeller

Installation

1.Before installing water pump, coat sealing surface

with silicon grease.

2.Install water pump assembly and tighten bolts to the

specified torque.

Torque: 25 N·m (2.5 kg·m/18 lb ft)

3.Timing belt

•Install timing belt, refer to timing belt installation

step in “Timing Belt" in this manual.

4. Connect radiator hose and replenish EC.

5. Connect battery ground cable.

(1) Water Pump Assembly

(2) O Ring (3) Bolt

Thermostat

Removal

1. Disconne ct batte ry ground cable.

2. Drain engine coolant from the radiator and engine.

3. Disconnect radiator hose from the inlet pipe.

4. Remove thermostat housing.

031RW012

Inspection

Suspend the thermostat in a water–filled container

using thin wire. Place a thermometer next to the

thermostat.

Do not directly heat the thermostat.

Gradually increase the water temperature. Stir the water

so that the entire water is same temperature.

Confirm the temperature when the valve first begins to

open.

Valve opening temperature 92°

°°

°C (197.6°

°°

°F)

))

)

Confirm the temperature when the valve is fully opened.

Valve full open temperature 107°

°°

°C (224.6°

°°

°F)

))

)

Make necessary repair and parts replacement if

extreme wear or damage is found during inspection.

Installation

1. Before installing thermostat, coat sealing surface

with silicon grease.

2. Install gasket.

3. Install thermostat housing and tighten bolts to the

specified torque.

Torque: 15 N·m (1.5 kg·m/11 lb ft)

4. Installation rubber hose.

5. Replenish engine coolant (EC).

6. Start engine and check for EC leakage.

Radiator

Radiator and Associated Parts

110RX004

Legend

EndOFCallout

Removal

1. Disconne ct batte ry ground cable.

2. Disconne ct coo li ng fan motor connecto r.

3. Loosen a drain plug to drain engine coolant.

4. Disconnect radiator inlet hose and outlet hose from

the engine.

5. Remove fan guide, clips on both sides and the

bottom lower with fan shroud.

6. Disconnect the reserve tank hose from radiator.

7. Remove bracket(2).

110RX003

(1) Radiator

(2) Bracket

(3) Cooling Fan Assembly

(4) Radiator Cap

(5) Radiator Hose

(6) Lower Fan Guide

8. Lift out the radiator assembly with hose, taking care

not to damage the radiator core with fan blade.

9. Remove rubber cushions on both sides at the

bottom.

Inspection

Radiator Cap

Measure the valv e 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: 5–8840–260 3–0

Check the condition of the vacuum valv e in the center of

the valv e seat side of the cap. If considerable rust or dirt

is found, or if the valv e seat cannot be moved by hand,

clean or replace the cap.

Valve opening vacuum kPa (psi) 1.96 ∼

∼∼

∼ 4.91 (0.28

∼

∼∼

∼ 0.71)

110RS006

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 sign 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.

Cap tester: 5–8840–0277–0

Adapter: 5–8840–2603–0

110RX002

Installation

1. Install rubber cushions on both sides of radiator

bottom.

2. Install radiator assembly with hose, taking care not

to damage the radiator core with a fan blade.

3. Install bracket and support the radiator upper tank

with the bracket and secure the radiator.

4. Connect res erve tank hose.

5. Install lower fan guide (6).

6.Connect radiator inlet hose and outlet hose to the

engine.

110RX003

7.Connect battery ground cable.

8.Pour engine coolant up to filler neck of radiator, and

up to MAX mark of reserve tank.

Important operation (in case of 100% engine

coolant change) procedure for filling with engine

coolant.

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 when 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 result it is suggested that the engine

cooling system be flushed at least once a year. It is

advisable to flash 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 to use Isuzu genuine anti-freeze

(ethylen-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 up 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 precausions

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 of 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 to the full, pull out the

filling hose and check to see if air trapped in the

system is disclodged and the coolant level goes

down. Should the coolant level go down, repeat

topping-up until there is no more drop in the

coolant level.

6.After directly 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 v apor 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.

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

through the needle position of water

thermometer, conduct a 5-minute idling again

and stop the engine.

Main Data and Specifications

General Specifications

Special Tool

Cooling system Engine Coolant forced circulation

Radiator (1 tube in row) Tube type corrugated

Heat radiation capacity 54,000 kcal/h (62.8 kw)

Heat radiation area 7.677m2 (0.878ft2)

Radiator front area 0.264m2 (0.028ft2)

Radiator dry weight (with fan) 32N (7.2lb)

Radiator cap valve opening pressure 93.3 ∼ 122.7kpa (13.5 ∼ 17.8ps i)

Engine coolant capacity 1.8lit (0.48 US gal)

Engine coolant pump Centrifugal type

Thermostat Bypass type

Engine coolant total capacity7.2lit (1.9 US gal)

ILLUSTRATION TOOL NO.

TOOL NAME

5–8840–0277–0

Test er; radiator cap

5–8840–2603–0

Adapter; radiator cap

Techline