2004 ISUZU TF SERIES belt

6 – 2 TROUBLESHOOTING
Basic Inspection Procedure
Follow the under inspection procedure, when the problem vehicle comes workshop.
Step Inspection point Inspection result YES NO
1 Check the check engine lamp Is the check engine lamp turn
ON ? Go to section
6E “On Board
Diagnostic
(OBD) System
Check" Go to Step 2
2 The battery fluid level and the
gravity Was the problem found? Re-charge the
battery or
replace the
battery Go to Step 3
3 The engine coolant capacity Was the problem found? Replenish the
engine coolant Go to Step 4
4 The engine oil level Was the problem found? Replenish the
engine oil Go to Step 5
5 The air cleaner element Was the problem found? Clean or
replace Go to Step 6
6 The piping fixing condition (oil,
vacuum and fuel piping) Was the problem found? Return normal
condition Go to Step 7
7 The drive belt tension and break Was the problem found? Re-adjust the
tension or
replace Go to Step 8
8 Go to section 6E “On Board
Diagnostic (OBD) System
Check” Was the problem found?
Verify repair Go to Step 9
9 Go to mechanical
troubleshooting chart Was the problem found?
Verify repair —

TROUBLESHOOTING 6 – 3
1. Hard Starting
Inspect the following items before diagnosis.
1. The battery conditions.
The terminal connection condition.
The battery charge condition or battery power weakness.
2. The fan belt loosen or broken.
3. The main fuse condition (open or not).
4. Fuel quantity level.
1–1 Starter motor inoperative
Step Action Value(s) Yes No
1 Check the starter switch.
Does the starter switch work? —
Go to Step 2 Repair or
replace the
starter switch
2 Check the starter relay.
Does the starter relay work? —
Go to Step 3 Repair or
replace the
starter relay
3 Check the magnetic switch.
Does the magnetic switch work? —
Go to Step 4 Repair or
replace the
magnetic
switch
4 Check the pinion gear condition on the starter motor.
Was the condition normal? —
Go to Step 5 Replace the
pinion gear
5 Check the brush wear or brush spring weakness.
Was the condition normal? —
Replace the
starter motor
assembly Repair or
replace the
brush or brush
spring

1-2 Starter motor operates but engine does not turn over
Step Action Value(s) Yes No
1 Check the engine internal seizure.
Was the engine seized? —
Repair or
replace seized
parts Check other
DTC by Tech
2 and go to
indicated DTC

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

TROUBLESHOOTING 6 – 13
10–3 Continuous noise
Step Action Value(s) Yes No
1 Was the fan belt tension OK? 9 – 13 mm
(0.35 – 0.51
in)
Go to Step 2 Adjust the fan
belt tension.
2 Was the cooling fan loose? — Tighten the
cooling fan Go to Step 3
3 Was noise coming from the generator? — Repair or
replace the
generator
and/or the
vacuum pump Go to Step 4
4 Was noise coming from the water pump? — Replace the
water pump Go to Step 5
5 Was noise coming from the cylinder head cover? — Readjust the
valve
clearance. Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC Solved

10-4 Slapping noise
Step Action Value(s) Yes No
1 Was noise coming from the cylinder head cover? — Go to Step 2 Go to Step 4
2 Were valve clearances correct? 0.4 mm
(0.016 in)
both intake
and exhaustAdjust the
valve
clearances Go to Step 3
3 Were the rocker arms damaged? — Replace the
rocker arms Go to Step 4
4 Was the flywheel fixing bolt loose? — Tighten the
fixing bolt. Go to Step 5
5 Was noise coming from the cylinder body? — Go to Step 6 Go to Step 10
6 Inspect the crankshaft bearing and/or crankshaft.
Was the crankshaft bearing and/or crankshaft worn?— Replace the
worn parts Go to Step 7
7 Inspect the connecting rod bearing and/or crankpin.
Was the connecting rod bearing and/or crankpin
worn? —
Replace the
worn parts Go to Step 8
8 Inspect the connecting rod small end bushing and/or
piston pin.
Was the connecting rod small end bushing and/or
piston pin worn? —
Replace the
worn parts Go to Step 9
9 Inspect the piston and/or cylinder liner.
Was the piston and/or cylinder liner worn or
damaged? — Replace the
worn or
damaged parts Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC Solved

6 – 16 TROUBLESHOOTING
14. Battery Charging and Noise Problem
Visual/physical check the following items before diagnosis.
The drive belt tension.
The battery terminals connection condition.
The ground connection condition.
The generator and the battery fastener condition.
The battery fluid level and specific gravity.
14-1 Battery No Charging
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Inspect the brush contact condition on the generator.
Was there poor contact between the brush and the
slip ring? — Repair or
replace the
brush and/or
the slip ring. Go to Step 3
3 Inspect the stator coil on the generator.
Was there an open circuit or the scorching on the
stator coil? —
Replace the
stator coil. Go to Step 4
4 Inspect the rotor coil on the generator.
Was there an open circuit or the scorching on the
rotor coil? —
Replace the
rotor coil. Go to Step 5
5 Inspect the rectifier on the generator.
Was the rectifier defective? — Replace the
rectifier Go to Step 6
6 Inspect the IC regulator.
Was the IC regulator defective? — Replace the IC
regulator. Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC. Solved

14-2 Battery Overcharging
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Inspect the terminal circuit.
Were the B and F terminals shorted? — Repair the
short circuit. Go to Step 3
3 Check the regulating voltage.
Was the IC regulator voltage excessive? — Replace the IC
regulator. Go to Step 4
4 Are any DTC stored? — Go to indicated
DTC. Solved

ENGINE MECHANICAL 6A – 29


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 C (F)
82 (180)
Oil Cooler Thermo Valve C (F)
76.5 (170)
EGR Cooler Thermo Valve C (F)
40 (104)

4. Check the thermostat full opening temperature.
Thermostat Full Opening Temperature C (F)
95 (203)
Oil Cooler Thermo Valve C (F)
90 (194)
EGR Cooler Thermo Valve C (F)
55 (131)
Valve Lift at Fully Open position mm (in)
9.5 (0.37)
Oil Cooler Thermo Valve mm (in)
4.5 (0.18)
EGR Cooler Thermo Valve mm in)
3.5 (0.14)



Drive Belt Adjustment
Check drive belts for wear or damage, and replace with
new ones as necessary. Check belts for tension, and
adjust as necessary.
1 Crankshaft damper pulley
2 Generator pulley
3 Cooling fan pulley
4 Oil pump pulley or idler pulley
5 Compressor pulley or idler pulley


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6A – 30 ENGINE MECHANICAL


Cooling Fan Pulley Drive Belt
Fan belt tension is adjusted by moving the generator.
Depress the drive belt mid-portion with a 98N (10 kg/22 lb)
force.
Cooling Fan Drive Belt Deflection mm (in)
New belt 4 - 7 (0.16 - 0.28)
Reuse belt 6 - 9 (0.24 - 0.35)
1 Crankshaft damper pulley
2 Generator pulley
3 Cooling fan pulley




A/C Compressor Drive Belt
Compressor belt tension is adjusted by moving the P/S
pumppulley.
Depress the drive belt mid-portion with a 98N (10 kg/22 Ib)
force.
A/C Compressor Drive Belt Deflection mm (in)
New belt 9 - 10 (0.35 - 0.39)
Reuse belt 12 - 13 (0.47 - 0.51)
1 Crankshaft damper pulley
2 P/S pump pulley
2 A/C Compressor pulley
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6A – 120 ENGINE MECHANICAL









4. Water Inlet Pipe
1) Tighten the water inlet pipe bolts to the specified
torque.
Suction Pipe Bolt Torque N·m(kg·m/Ib ft)
19 (1.9/14)





5. Generator and Adjusting Plate
1) Install the generator to the bracket (1).
2) Temporarily tighten the generator bolt (2) and
adjusting plate bolts (3).
The bolts will be finally tightened after installation of
the cooling fan drive belt.



3) Connect the vacuum pump rubber hose (4) to the
vacuum pump (5), and the oil pan (6).
6. Vacuum Pump Oil Return Hose
Connect the vacuum oil pipe (7) to the vacuum pump, and
the cylinder body

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7. Compressor Bracket
1) Install the compressor bracket to the cylinder head.
2) Tighten the bracket bolts to the specified torque.
Bracket Bolt Torque N·m(kg·m/Ib ft)
M8
1.25
19 (1.9/14)
M10
1.25
40 (4.1/30)











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