engine ISUZU KB P190 2007 Workshop Repair Manual

Engine Cooling – V6 Engine Page 6B1–60

Transmission Oil Cooler Leak Test
If the transmission oil cooler is suspected of leaking oil, test it before the radiator is replaced, as follows:
1 Disconnect oil cooler pipes at the flexible hose connections. Refer to 3.14 Flexible Transmission Cooler Hose, in this Section.
2 Plug one of the connections, using a blocked pipe fitting and attach an air supply to the other flexible hose.
3 Remove coolant filler cap and check that the coolant is filled to the coolant filler cap filler neck.
4 Apply air pressure gradually, increasing up to an absolute maximum of 110 kPa. If bubbles appear in radiator neck, the oil cooler is leaking and the radiator assembly must be replaced.
Transmission Oil Cooler Seal Replacement.
It is strongly recommended that the transmission oil cooler connector fittings to the right-hand side radiator header tank,
not be disturbed. If coolant is found to leak from either of these two areas, then the radiator should be replaced.


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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–61

4 Engine Cooling System
Diagnosis
4.1 Poor Heater Operation
Little or no heat coming from the heater, especially at idle could be an indication of a cooling system problem.
As the coolant level begins to get lower than normal, air enters the system to replace the missing coolant. The heater
core is one of the highest parts of the cooling system and therefore, the first area to lose coolant circulation.
At first, with a small amount of coolant loss, lack of heat will be most noticeable at idle. As driving speed increases, the
engine pumps more coolant and more heat is now able to pass through the heater core.
If coolant level drops even lower, heater operation will become less effective, even during normal driving. Cooling and
engine systems can be adversely affected if problem is not corrected before overheating occurs.
4.2 Leaking Cylinder Head Gasket
Combustion gases leaking past the cylinder head gasket can pressurise the cooling system, forcing coolant out of the
system and into the coolant recovery reservoir.
Indications are air bubbles in the coolant or an overflow condition of the recovery reservoir.
4.3 Question the Customer
To avoid needless time and cost in diagnosing cooling system complaints, the customer should be questioned about
driving conditions that place abnormal loads on the cooling system.
1 Is overheating occurring after prolonged idle, in gear, with air conditioning system operating?
If answer is YES – instruct owner on driving techniques that would avoid overheating such as:
• Idle in neutral as much as possible – increase engine rpm to get higher air flow (due to an increase in voltage
to the fan) and coolant flow through the radiator
• Turn air conditioning system off during extended idling periods if overheating is indicated on temperature
gauge. Further diagnostic checks should not be required
2 Is overheating occurring after prolonged driving in slow city traffic, traffic jams, parades, etc?
If answer is YES, explain driving technique to the customer, that would avoid overheating – same as for prolonged idle – No.1. Further diagnostic checks should not be required.
4.4 Diagnostic Chart
If none of the above conditions apply, refer to the following Diagnosis Chart.
To effectively use this chart, question the customer to determine which of the following three categories apply to the
complaint:
1 If complaint is hot indication on temperature gauge.
W as temperature reading accompanied by boiling?
• If answer is YES, go to overheating on diagnosis chart
• If answer is NO, check temperature gauge and sender
2 If complaint is boiling – go to overheating on diagnosis chart.
3 If complaint is coolant loss. Determine if customer is filling the system correctly.
4 If incorrect filling is not the problem, go to coolant loss in the diagnosis chart.

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–62


Refer to 3.1 Service Notes in this Section, for
important safety items before removing the
coolant filler pressure cap or servicing the
system.

The cooling system is designed to operate at
120 –
––
–
130 kPa and a maximum temperature
not above 130 °
°°
°
C.
Cooling System Diagnosis
Step Action Result Yes No
1
Check Temperature gauge reading High Temp.
Low Temp. Go to Step 2
Go to Step 6 –
2
Check drive belt condition and tension. Refer to 6A1
Engine Mechanical. To Specification Go to Step 3 Replace drive
belt or
tensioner.
3 Check coolant Boiling Go to Step 4 Go to Step 5
4 Check coolant level. Refer to 3.2 Coolant
Maintenance in this Section. Low Go to Step 10 Go to Step 6
5
Check coolant filler cap. Refer to 3.7 Pressure
Testing – Coolant Filler Cap Pressure Testing in this
Section OK? Go to Step 8
Replace
Coolant filler
cap
6 Check thermostat. Refer to 3.8 Thermostat in this
Section. OK? Go to Step 9 Go to Step 13
7
Check Engine Coolant Temperature (ECT) sensor.
Refer to 6C1 Engine Management General Information. Faulty Replace Go to Step 12
8
Check cooling fan operation. Refer to 6C1 Engine
Management General Information. Operational Go to Step 10 Repair
9
Check for collapsed upper or lower radiator hose. Collapsed Replace Go to Step 13
10 Visual system check Leaks Go to Step 13 Go to Step 11
11 Check coolant concentration. Refer to 3.2 Coolant
Maintenance. To Specification Go to Step 12 Correct
Concentration Level
12 Check radiator core for bent fins, dirt, bugs or other
obstructions. Obstructed Clean or
straighten Go to Step 14
13
Pressure Test cooling system. Refer to 3.7 Pressure
Testing in this Section. Leaks Repair System OK
14
If none of the above require repair, the problem is
complex or of a major nature.
Refer to 4.5 Problems Not Requiring Disassembly of
Cooling System or 4.6 Problems Requiring Disassembly
of Cooling System. – – –

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–63

4.5 Problems Not Requiring Disassembly of
Cooling System
1 Large obstructions blocking radiator or condenser airflow.
• Auxiliary oil coolers
• License plate
• Obstruction of radiator grille, for example, driving lights or mud
2 Loose, damaged or missing air chute side panels.
3 Missing or damaged air baffle.
4 Cracked or loose coolant recovery system hose.
5 Leaking heater component such as the heater core or water valve.
4.6 Problems Requiring Disassembly of Cooling System
1 Damaged cooling fan or faulty motor operation.
2 Pressure test cooling system.
3 Defective coolant pump.
• Eroded or broken impeller vanes
• Failed bearing or seal – check for shaft or bearing end play
4 Internally blocked radiator core.
5 Obstruction of coolant recovery system.
6 Internal system leaks.
• Head gaskets
• Cracked cylinder block
• Engine front cover
• Intake manifold gaskets
7 Blocked coolant passages in cylinder heads or block – remove cylinder heads and check.
4.7 Black Light and Dye Leak Diagnosis Method
It is strongly recommended that this diagnostic method be used to diagnose fluid leaks. This method is a proven and
reliable method that identifies the specific leak source.
The black light kit can be used for the leak detection of a number of fluids, when used with the appropriate tracer dye.
Examples are: Coolant, Engine Oil, Automatic Transmission Fluid and Air Conditioning Refrigerant (R134A).
The following is a summary of the steps involved in detecting a cooling system fluid leak using black light and dye:
1 Pour specified amount of dye into the cooling system via the coolant filler cap on the outlet housing. Refer 3.1 Service Notes in this Section.
2 Road test the vehicle under normal operating conditions.
3 Direct the light towards the suspect area. The fluid leak will appear as a brightly coloured path leading from the source.
4 Repair fluid leak and recheck to ensure that leak has been rectified.
5 Refer to the manufacturer’s directions when using this method.

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–64

5 Specifications
General
Coolant Filler Cap Pressure Rating .............................................................................120 kPa
Cooling System Capacity
Automatic Transmission ........................................................................................ 9.9 litres
Manual Transmission .......................................................................................... 10.3 litres
Coolant Corrosion Inhibitor Quantity W hen Refilling System Automatic Transmission Models......................................................................... 5 litres
Manual Transmission Models .......................................................................... 5.2 litres
NOTE
DEX-COOL® long life coolant or equivalent such
as Extended Life Anti-freeze Coolant, conforming
to GM Specification 6277M, must be used when
changing coolant.
Thermostat Type...............................................................................................Power element (wax pellet)
Start to Open at ......................................................................................................... 82 ± 2 ° C
Fully Open at .......................................................................................................... 95° C ma x.
Coolant Pump
Type........................................................................................................................ Cen trifugal
Drive ................................................................................................ Multi-Vee Serpentine Belt
Bearing Type .................................................................................... Double Row Ball Bearing
Radiator
Core type ......................................................................................... Aluminium crossflow core
Overall width ................................................................................................................ 66 4 mm
Core width.................................................................................................................... 5 10 mm
Overall height............................................................................................................... 60 2 mm
Core height .................................................................................................................. 51 2 mm
Core thickness ............................................................................................................... 27 mm
Plastic Tanks .............................................................................. Nylon 6.6 (30% Glass Filled)
Radiator Hoses Lower Upper
Number ............................................................................... One............................. One
Type................................................................................ Moulded ...................... Moulded
Inside diameter ................................................................. 34 mm ........................ 34 mm

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–65

Engine Cooling Fan

Rotational Speed (with 13 ± 0.26 volts negative polarity duty signal applied)

– Stage 1 (25% Duty) ..................... 1,100 ± 110 rpm (3 ± 0.3A)
– Stage 2 (25% Duty) ..................... 1,600 ± 160 rpm (7 ± 0.7A)
– Stage 3 (25% Duty) ..................... 2,100 ± 210 rpm (15 ± 1.5A)
– Stage 4 (25% Duty) ..................... 2,400 ± 240 rpm (22 ± 2.2A)


Number of Blades ............................................................................................................... .... 5
Fan – Design ................................................................. Asymmetrical spaced, curved blades
Material ................................................................................... Nylon Glass, Mineral reinforced
Diameter ...................................................................................................................... 5 00 mm
Fan Motor – Type ..................................................................................................... Brushless
Fan Motor – Power ......................................................................................................... 400W
Fan Motor – Input signal ................................................................................................ 100Hz
Housing ..........................................................Semi-sealed, zinc-coated steel with drain hole
Direction of Rotation .....................................Counter clockwise (as viewed from drivers seat)

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Engine Cooling – V6 Engine Page 6B1–66

6 Torque Wrench Specifications
N.m
Coolant Outlet housing to Engine Outlet Attaching Bolts............................... 10
Coolant Pump to Front Cover Attaching Bolts ............................................... 10
Coolant Pump Pulley Attaching Bolts ............................................................ 12
Coolant Inlet Pipe to Thermostat Housing Attaching Bolt .............................. 23
Fan Motor Assembly to Shroud Attaching Screws .......................................... 5
Heater Pipe Assembly to Thermostat Housing Attaching Bolts ..................... 10
Heater Pipe Assembly to Cylinder Head Attaching Bolt ................................ 35
Thermostat Housing to Engine Block Attaching Bolts.................................... 10
Rear Engine Harness .................................................................................... 15
Engine Harness Ground Terminal ................................................................. 12
Coolant Inlet Pipe To Engine Block Bolt ........................................................ 25
Transmission Cooler Lines Bracket .............................................................. 23


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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–67

7 Special Tools
Tool number Illustration Description Classification
AU505
Coolant Tester
Used for testing the coolant
concentration level.
Previously released. Mandatory
AU525
Quick Connect Release Tool
Used to release the quick connect
fittings on automatic transmission fluid
cooler lines at the radiator end, when
fitted.
Previously released. Mandatory
BT3373–F

Belt Tension Gauge
Used when checking drive and
accessory belt tension and
adjustments.
Previously released. Desirable
J 26568 Refractometer
Used for testing coolant concentration
level.
Previously released, as AU 435. Mandatory
J28431–B Fluid Dye
Available in 24 x 1-ounce bottles.
Used in conjunction with a black light
such as J42220 to locate the source
of various fluid leaks.
Previously released. Desirable
J42220 Black Light, Leak Detection Lamp
Used with dye, J28431–B to locate the
source of various vehicle fluid leaks.
Previously released. Desirable
N/A Cooling System Pressure Tester
Previously released. Commercially available. Mandatory


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ISUZU KB P190 2007

Fuel System – V6 Page 6C – 2

4.6 Evaporative Emission Control Canister............................................................................................................. 27
Remove ................................................................................................................................................................. 27
Service Check .................................................................................................................. .................................... 28
Reinstall ................................................................................................................................................................ 29
4.7 Fuel Tank Siphon Procedure ..................................................................................................... ......................... 30
4.8 Fuel Filler Cap ...................................................................................................................................................... 32
Remove ................................................................................................................................................................. 32
Inspection ......................................................................................................................................................... 32
Reinstall ................................................................................................................................................................ 32
4.9 Fuel Lines ..................................................................................................................... ........................................ 33
Remove ................................................................................................................................................................. 33
Fuel Tank Lines ................................................................................................................ .................................... 34
Reinstall ................................................................................................................................................................ 34
Fuel Line Routing.............................................................................................................. ................................... 35
Bell Housing Fuel Lines ........................................................................................................ .............................. 36
Engine Bay Fuel Lines......................................................................................................................................... 36
4.10 Rollover Valve ...................................................................................................................................................... 37
5 Specifications .......................................................................................................................................38
6 Torque Wrench Specifications................................................................................................... .........39
7 Special Tools ........................................................................................................................................40



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ISUZU KB P190 2007

Fuel System – V6 Page 6C – 3

1 General Information
Description
Fuel is injected into the engine by separate fuel injectors that are mounted in the intake manifold (common chamber).
Fuel is supplied to the injectors under pressure from the fuel tank through the fuel lines and the fuel rail, which is
attached to the top of the common chamber.

A fuel pressure control valve is installed on the fuel rail to maintain fuel line pressure across the injectors under all
operating conditions. Fuel pressure is maintained by controlling the amount of fuel that is supplied from the fuel tank,
based on the demand of the engine via the engine control module (ECM).

Two interchangeable “O” rings are used on the fuel injector and must be replaced when the injectors are removed.
The Multiport Fuel Injection system utilizes an injection system where the injectors turn on at every crankshaft revolution.
The ECM controls the injector on time so that the correct amount of fuel is metered depending on driving conditions.
The V6 engine is designed to use only unleaded petrol.

Unleaded petrol must be used for correct emission control system operation and its use will also minimize spark plug
fouling and extend engine oil life.

Using leaded petrol can damage the emission control system and could void the vehicle warranty. All vehicles are
equipped with an Evaporative Emission Control System. The purpose of the system is to minimize the escape of fuel
vapours into the atmosphere.
Service Precautions
• Use extreme care when working on the fuel system and follow all safety precautions.
• W hen working on the fuel system, disconnect the battery ground cable except for tests where battery voltage is
required.
• Always keep a dry chemical (class B) fire extinguisher near the work area.
• Relace all fuel lines and fittings with the same type of line and fitting as those removed.
• Clean and inspect “O” rings carefully and replace if required.
• Always depressurize the fuel lines before servicing any fuel system components.
• Do not attempt any repairs on the fuel system until, all warnings and instructions, relating to that repair have been
read and ensure all notices and cautions are adhered to.
• Do not allow any naked frames or sparks near the work area when working on the fuel system.
• If draining of the fuel system is required, this should be done in a well ventilated area.
• Protect the fuel lines and associated parts from thermal damage, spattering when welding.

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