Komatsu PC138US-11 Operation & Maintenance Manual page 315

OPERATION
Problem
Starting motor rotates but engine
does not start.
Exhaust gas color is white or bluish.
Exhaust gas turns black from time to
time.
Combustion makes breathing sound
from time to time.
Abnormal noise is generated.
(combustion or mechanical)
Engine stalls during operation.
IF MACHINE MONITOR SHOWS WARNING DISPLAY
When the action level display (1) or caution lamp (2) is shown
on the display of the machine monitor, press switch F5 to dis-
play the "Current Abnormality" and check the details and reme-
dy.
For the contents of the action level display and caution lamp,
see "WARNING DISPLAY (3-17)".
Main causes
Lack of fuel
Air in fuel system
Defective fuel injection pump or de-
fective nozzle
Starting motor turns engine sluggish-
ly.
Preheating pilot lamp does not light
up.
Defective compression
(Defective valve clearance)
Excessive oil in oil pan
Improper fuel
Clogged air cleaner element
Defective nozzle
Defective compression
Defective turbocharger
Defective nozzle
Low grade fuel being used
Overheating
Damage inside muffler
Excessive valve clearance
Clogging of pre-filter or main filter
Defective engine and fuel circuit
WENAM00111
TROUBLES AND ACTIONS
Remedy
Add fuel. See CHECKS BEFORE
STARTING.
Repair place where air is sucked in.
See EVERY 500 HOURS MAINTE-
NANCE.
Replace pump or nozzle. (*)
See PHENOMENA AND ACTIONS
FOR ELECTRICAL SYSTEM.
See PHENOMENA AND ACTIONS
FOR ELECTRICAL SYSTEM.
Adjust valve clearance. (*)
Set oil to specified level. See
CHECKS BEFORE STARTING.
Replace with specified fuel.
Clean or replace. See WHEN RE-
QUIRED.
Replace nozzle. (*)
See the above section on defective
compression. (*)
Clean or replace turbocharger. (*)
Replace nozzle. (*)
Replace with specified fuel.
See the above section on "Indicator
of engine coolant temperature gauge
is in red range".
Replace muffler. (*)
Adjust valve clearance. (*)
Replace filter cartridge.
Check, repair. (*)
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