ISUZU TF SERIES 2004 Workshop Manual

TROUBLESHOOTING 6 – 11
9. Oil Pressure Does Not Rise
Step Action Value(s) Yes No
1 Was the oil pressure warning lamp working OK? —
Go to Step 2 Replace the oil
pressure
warning lamp
2 Does the oil filter element clog? — Replace the oil
filter element Go to Step 3
3 Does the relief valve open? — Repair or
replace the
relief valve Go to Step 4
4 Does the oil strainer clog? — Clean or
replace the oil
strainer Go to Step 5
5 Was the oil pump working OK? (The pump related
parts worn etc.) —
Go to Step 6 Repair or
replace the oil
pump.
6 Was the rocker arm and/or relation parts worn? — Replace the
rocker arm
and/or relation
parts Go to Step 7
7 Was the camshaft and/or relation parts worn? — Replace the
camshaft
and/or relation
parts Go to Step 8
8 Was the crankshaft and/or relation parts worn? — Replace the
crankshaft
and/or relation
parts Go to Step 9
9 Are any DTC stored? — Go to indicated
DTC Solved

Table of pressure unit
Pressure kPa (kg/cm
2) 100
(1.0) 980
(10.0)
Resistance ohm 81 30
Electric current A 63.5 106.7

6 – 12 TROUBLESHOOTING
10. Abnormal Engine Noise
10–1 Engine knocking
Step Action Value(s) Yes No
1 Was the injection nozzle pressure or injection spray
pattern OK? —
Go to Step 2 Replace the
injection nozzle
2 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm Go to Step 3 Replace the
cylinder head
gasket or
piston ring
3 Are any DTC stored? — Go to indicated
DTC Solved

10–2 Gas leakage noise
Step Action Value(s) Yes No
1 Was the exhaust pipe loose or broken? — Retighten or
replace the
exhaust pipe Go to Step 2
2 Was the exhaust manifold loose? — Retighten or
replace the
exhaust
manifold. Or
replace the
exhaust
manifold
gasket Go to Step 3
3 Was the injection nozzle loose? — Retighten or
replace the
injection nozzle
fixing bolt Go to Step 4
4 Was the cylinder head gasket broken? — Replace the
cylinder head
gasket Go to Step 5
5 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 – 14 TROUBLESHOOTING
10-5 Excessive turbocharger noise
The vibration noise (the air aspiration noise) occurred when turbocharger rotates, it is normal condition of the
turbocharger, no necessary any actions.
Step Action Value(s) Yes No
1 Was the excessive noise coming from the
turbocharger? —
Go to Step 2 Go to Step 10
2 Inspect the fixing bolts and bands.
Was any problem found? — Tighten the
loose parts Go to Step 3
3 Was the intake or exhaust system gasket damaged?— Replace the
damaged
gasket. Go to Step 4
4 Inspect rotation parts condition.
Was the turbine wheel rotation rough? — Replace the
turbocharger. Go to Step 5
5 Inspect the turbine wheel.
Was the turbine wheel rubbing against housing? — Replace the
turbocharger. Go to Step 6
6 Was the turbine wheel damaged? — Replace the
turbocharger. Go to Step 7
7 Were there carbon deposits in the turbine or
compressor housing? — Clean or
replace the
turbocharger. Go to Step 8
8 Inspect the oil supply condition.
Was the oil feed pipe clogged? — Repair or
replace the oil
feed pipe. Go to Step 9
9 Was the turbine shaft bearing worn? — Replace the
turbocharger. Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC Solved

11. Rotating Part Wear of Turbocharger
Step Action Value(s) Yes No
1 Inspect engine oil.
Was it contaminated with foreign materials? — Replace the
engine oil Go to Step 2
2 Was the recommended engine oil grade/viscosity
being used? API CD or
ISUZU
genuine/
10W–30
Go to Step 3 Replace the
engine oil
3 Was the oil feed pipe restricted? — Clean or
replace the oil
feed pipe Go to Step 4
4 Was the oil seal of turbocharger defective? — Replace the oil
seal Go to Step 5
5 Was the center housing oil drain passage clogged? — Clean center
housing or
replace the
turbocharger Go to Step 6
6 Was there oil sludge and/or coking on the turbine
shaft? — Replace the
turbocharger Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC Solved

TROUBLESHOOTING 6 – 15
12. Oil Leakage from Turbocharger
Step Action Value(s) Yes No
1 Inspect the oil leakage area.
Was the oil feed pipe eye bolt loose or the gasket
broken? — Tighten the eye
bolt or replace
the gasket. Go to Step 2
2 Were the V band fixing faces tight? — Tighten band
or replace the
turbocharger Go to Step 3
3 Was there oil leakage from the flange of the turbine
housing? — Replace the
turbocharger Go to Step 4
4 Was there oil leakage from the flange of compressor
housing? — Tighten the bolt
and/or hose
clamp. Go to Step 5
5 Are any DTC stored? — Go to indicated
DTC Solved

13. Insufficient Acceleration and/or Lack of Power due to turbocharger
Step Action Value(s) Yes No
1 Inspect the air or exhaust route.
Was the air and/or exhaust gas piping loose? — Tighten flange
bolts or hose
clamp. Go to Step 2
2 Inspect the work of waste gate valve control.
Was there rust on the linkage rod or pin of the waste
gate valve? —
Replace the
turbocharger Go to Step 3
3 Was air leakage found from the actuator piping? — Repair or
replace the
actuator pipe or
hose/ Go to Step 4
4 Inspect the inside of the turbocharger.
Was the turbine shaft end nut loose? — Replace the
turbocharger Go to Step 5
5 Were the turbine blades bent? — Replace the
turbocharger Go to Step 6
6 Was the turbine wheel rubbing against housing? — Replace the
turbocharger Go to Step 7
7 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

TROUBLESHOOTING 6 – 17
14-3 Battery Under 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 intermittent contact between the brush
and the slip ring? — Repair or
replace the
brush holder
assembly. Go to Step 3
3 Inspect the rotor coil on the generator.
Was there a short circuit in the rotor coil? — Repair or
replace the
rotor coil. Go to Step 4
4 Inspect the stator coil on the generator.
Was there an open circuit or the short circuit on the
stator coil? — Repair or
replace the
stator 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 on the generator.
Was the IC regulator defective? — Replace the IC
regulator. Go to Step 7
7 Was the electrical load excessive? — Replace more
higher capacity
generator. Go to Step 8
8 Are any DTC stored? — Go to indicated
DTC. Solved

14-4 Battery Unstable Charging Current
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 rotor coil on the generator.
Was there the short circuit or an open circuit in the
rotor coil? — Repair or
replace the
rotor coil. Go to Step 4
4 Inspect the stator coil on the generator.
Was there an open circuit or the short circuit in the
stator coil? — Repair or
replace the
stator coil. Go to Step 5
5 Inspect the connection between the rectifier and
stator coil on the generator.
Was there a loose connection between the rectifier
and stator coil ? —
Repair the
loose
connection. Go to Step 6
6 Inspect the IC regulator on the generator.
Was the IC regulator defective? — Replace the IC
regulator. Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC. Solved

6 – 18 TROUBLESHOOTING
14-5 Charging System Noise
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Was there intermittent noise or continuous noise and
that could be identified clearly by increasing and
decreasing engine speed? —
Replace the
bearing. Go to Step 3
3 Was there a growling sound and does this sound
stop when the connector was disconnected? — Replace the
stator coil. Go to Step 4
4 Was intermittent sound heard when the generator
was running? — Replace the
brush and/or
slip ring. Go to Step 5
5 Was frictional sound heard when generator was
running? — Clean the slip
ring or replace
the brush. Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC. Solved

TROUBLESHOOTING 6 – 19
15. Starter Motor Problem
Visual/physical check the following items before diagnosis.
The battery terminals connection condition.
The ground connection condition.
The starter motor or the battery fastener condition.
The battery fluid level and specific gravity.
15-1 Starter motor pinion engages to ring gear but engine does not turn over
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Check the contact condition between the brush and
the commutator.
Was the brush and the commutator contact
intermittent? — Replace the
brush or repair
the
commutator. Go to Step 3
3 Were the brush and the commutator contact faces
dirty?
—
Clean contact
face Go to Step 4
4 Was the pinion clutch slipped? — Replace the
pinion clutch Go to Step 5
5 Inspect the armature field coil.
Was there an open circuit or a short circuit in the
armature field coil? — Repair or
replace the
armature field
coil. Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC. Solved

15-2 Incorrect pinion and ring gear engagement
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Inspect the pinion and the ring gear teeth.
Were the pinion and/or the ring gear teeth worn or
broken? —
Replace the
wron parts. Go to Step 3
3 Inspect the pinion gear return movement.
Was the pinion gear return movement incorrect? — Adjust or
replace the
movement
parts. Go to Step 4
4 Are any DTC stored? — Go to indicated
DTC. Solved

6 – 20 TROUBLESHOOTING
15-3 Starter motor continues to run after the starter switch is turned off
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Inspect the magnetic switch contact point.
Was the contact point seized? — Repair or
replace the
magnetic
switch. Go to Step 3
3 Inspect the starter switch.
Was the starter switch defective? — Replace the
starter switch. Go to Step 4
4 Are any DTC stored? — Go to indicated
DTC. Solved

15-4 Excessive commutator sparking
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical
check
2 Inspect the contact condition between the brush and
the commutator.
Was the brush and the commutator contact
intermittent? — Replace the
brush or repair
the
commutator. Go to Step 3
3 Was there the slag accumulation on the contact
face? — Clean the
contact face or
replace the
brush. Go to Step 4
4 Was the brush holder loose? — Repair the
brush holder Go to Step 5
5 Inspect the commutator.
Was there excessive wear or pitting? — Repair or
replace the
commutator. Go to Step 6
6 Was there loose the solder on the commutator? — Clean and
repair Go to Step 7
7 Inspect the armature shaft.
Was the run-out of armature shaft outside the
standard value due to worn bearing ? —
Replace the
bearing Go to Step 8
8 Are any DTC stored? — Go to indicated
DTC. Solved