overheating ISUZU KB P190 2007 Workshop Repair Manual

TROUBLESHOOTING 6 – 1




BASIC INSPECTION PROCEDURE....6– 2

1. HARD STARTING ............................6– 3

1-1.Starter Motor Inoperative ..........6– 3

1-2. Starter Motor Operates But
Engine Does Not Turn Over ...........6– 3

1-3. Engine Turns Over But Does
Not Start Engine ..............................6– 4

2. UNSTABLE IDLING .........................6– 5

3. INSUFFICIENT POWER ..................6– 6

4. EXCESSIVE FUEL
CONSUMPTION..................................6– 7

5. EXCESSIVE OIL CONSUMPTION ..6– 8

6. OVERHEATING ...............................6– 9

7. WHITE EXHAUST SMOKE..............6– 9

8. DARK EXHAUST SMOKE ...............6– 10

9. OIL PRESSURE DOES NOT RISE..6– 11

10. ABNORMAL ENGINE NOISE ........6– 12

10-1. Engine Knocking ....................6– 12

10-2. Gas Leakage Noise .................6– 12

10-3. Continuous Noise ...................6– 13

10-4. Slapping Noise ........................6– 13

10-5. Excessive Turbocharger
Noise ................................................6– 14
11. ROTATING PART WEAR OF
TURBOCHARGER.............................. 6– 14

12. OIL LEAKAGE FROM
TURBOCHRGER ................................ 6– 15

13. INSUFFICIENT ACCELERATION
AND/OR LACK OF POWER DUE
TO TURBOCHARGER........................ 6– 15

14. BATTERY CHARGING AND
NOISE PROBLEM .............................. 6– 16

14-1. Battery No Charging ............... 6– 16

14-2. Battery Overcharging ............. 6– 16

14-3. Battery Under Charging ......... 6– 17

14-4. Battery Unstable Charging
Current ............................................. 6– 17

14-5. Charging System Noise ......... 6– 18

15. STARTER MOTOR PROBLEM ..... 6– 19

15-1. Starter Motor Pinion Engages
to Ring Gear But Engine Does
Not Turn Over .................................. 6– 19

15-2. Incorrect Pinion And Ring
Gear Engagement ........................... 6– 19

15-3. Starter Motor Continues To
Run After The Starter Switch Is
Turned Off........................................ 6– 20

15-4. Excessive Commutator
Sparking .......................................... 6– 20


SECTION 6
TROUBLESHOOTING
TABLE OF CONTENTS
PAGE PAGE

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ISUZU KB P190 2007

TROUBLESHOOTING 6 – 9
6. Overheating
Step Action Value(s) Yes No
1 Was the engine coolant level OK? —
Go to Step 2 Replenish the
coolant
2 Was the water leakage or the radiator restriction found? (Include radiator cap) —
Repair or
replace the
leakage part. Go to Step 3
3 Was the fan belt slippage found? — Tension or
replace the fan belt. Go to Step 4
4 Was the fan clutch working completely? —
Go to Step 5 Replace the fan
clutch
assembly.
5 Was the oil leakage found from fan clutch? — Replace the fan
clutch
assembly Go to Step 6
6 Was the thermostat working normally? —
Go to Step 7 Replace the
thermostat.
7 Was the water pump working OK? —
Go to Step 8 Replace the
water pump assembly.
8 Was the restriction by the foreign materials in the cooling system found? For example, clog the water
hose between the cylinder body and radiator etc.. —
Clean or
replace the clog part. Go to Step 9
9 Was the water leakage found from the sealing cap
on the cylinder body? —
Replace the
sealing cap or replace the
cylinder body. Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC. Solved

7. White Exhaust Smoke
Step Action Value(s) Yes No
1 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at 200 rpm
Go to Step 2 Readjust the
valve clearance or replace the cylinder head gasket or
cylinder liner or
piston or piston ring or valve and relation parts.
2 Was the PCV (Positive Crankcase Ventilation) valve working completely? —

Go to Step 3 Repair or
replace the
PCV valve.
3 Was the turbocharger working completely? —
Go to Step 4 Replace the
turbocharger.
4 Are any DTC stored? — Go to indicated
DTC Solved


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ENGINE COOLING 6B – 7
DIAGNOSIS
Engine Cooling Trouble
Symptom Possible Cause Action
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
Engine overheating
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Faulty thermostat Replace Engine slow to warm–up
Thermo unit faulty Replace



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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

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6B-6 ENGINE COOLING (4JK1/4JJ1)
Diagnosis
Engine Cooling Trouble
Condition Possible Cause Correction
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
Engine overheating
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Faulty thermostat Replace Engine slow to warm–up
Thermo unit faulty Replace


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ISUZU KB P190 2007

ENGINE COOLING (4JK1/4JJ1) 6B-15
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: 93.3 - 122.7 kPa (0.95 - 1.25 kg / cm
2 / 13.5 -
17.8 psi)
Cap tester: 5–8840–0277–0
Adapter: 5–8840–2603–0
Check the condition of the vacuum valve in the cente
r
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: 1.96 - 4.91 kPa (0.02 - 0.05 kg / cm
2 / 0.28 - 0.71
psi)



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 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 (2.0 kg / cm2 / 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.



110RS005


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6-8 ENGINE DIAGNOSIS (C24SE)
Condition Possible cause Correction
Engine overheating Level of Engine Coolant too low Replenish
Thermo switch or fan motor
defective Replace
Thermostat
defective Replace
Engine Coolant pump defective Correct or replace
Radiator clogged Clean or replace
Radiator filter cap defective Replace
Level of oil in engine crankcase
too low or wrong oil in engine Change or replenish

Resistance in exhaust system
increased Clean exhaust system or replace
defective parts
Throttle Position Sensor
adjustment incorrect Adjust Wide Open Throttle switch
setting
Throttle Position Sensor circuit
open or shorted Correct or replace

Cylinder head gasket damaged Replace
Cooling Fan clutch defective Replace
Fan belt slipping Adjust tension of V-belt or replace
V-belt
Engine overcooling Thermostat defective Replace (Use a thermostat set to
open at 92 °C (197.6 °F))
Engine lacks compression - Refer to Hard Start
Others Tire inflation pressure abnormal Adjust to recommend pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level of oil in engine crankcase
too high Correct level of engine oil

Engine Noisy
Abnormal engine noise often consists of various
noises originating in rotating parts, sliding parts and
other moving parts of the engine. It is, therefore,
advisable to locate the source of noise systematically.
Condition Possible cause Correction
Noise from crank journals or from
crank bearings
(Faulty crank journals and crank
bearings usually make dull noise
that becomes more evident when
accelerating) Oil clearance increased due to
worn crank journals or crank
bearings Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crankshaft out of round Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crank bearing seized Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing


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6-10 ENGINE DIAGNOSIS (C24SE)
Troubleshooting Procedure
Condition Possible cause Correction
Piston pin noise
(Piston makes noise each time it
goes up and down) Piston pin or piston pin hole worn Replace piston, piston pin and
connecting rod assy

Troubleshooting Procedure
The slapping sound stops when spark plug on bad
cylinder is shorted out.
Condition Possible cause Correction
Timing belt noise Timing belt tension is incorrect Replace pusher or adjust the
tension pulley or replace timing
belt
Tensioner bearing defective Replace
Timing belt defective Replace
Timing wheels defective Replace
Timing belt comes in contact with
timing cover Replace timing belt and timing
cover
Valve noise Valve and valve guide seized Replace valve and valve guide
Valve spring broken Replace
Valve seat off-positioned Correct
Crankshaft noise Crankshaft end play excessive
(noise occurs when clutch is
engaged) Replace thrust bearing
Engine knocking
Preignition due to use of spark
plugs of inadequate heat range Install Spark Plugs of adequate
heat range
Fuel too low in octane rating Replace fuel
Wide Open Throttle enrichment
system failure Refer to Section 6E

Selection of transmission gear
incorrect Caution operator or incorrect gear
selection
Engine overheating Refer to "Engine Lacks Power"
Others Water pump defective Replace
V-belt slipping Adjust tension of V-belt or replace
V-belt


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ENGINE COOLING 6B-5
Diagnosis
Engine Cooling Trouble
Condition Possible cause Correction
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 cylinder head gasket Replace
Loosen V-belt tension Adjust belt tension or replace.
Collapsed hoses Replace
Faulty Fan clutch Replace
Engine overcooling Faulty thermostat Replace
Engine slow to warm-up Faulty thermostat Replace
Thermo unit faulty Replace


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6B-12 ENGINE COOLING


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 – 103.0
(13.5 – 15.7)
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) 1.9 - 4.9
(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 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


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ISUZU KB P190 2007