
38 RENR9348-01
Troubleshooting Section
Turbocharger
Check for turbocharger shaft seal leakage. Remove
the air inlet piping and the exhaust outlet piping from
the turbochar
ger. Check the compressor wheel and
the turbine for evidence of an oil leak. If necessary,
repair the turbocharger or replace the turbocharger.
Refer to Syst
ems Operation/Testing and Adjusting.
Internal Engine Wear
Internal engine wear can cause excessive oil leakage
into the combustion area of the cylinders. Excessive
wear on the fo
llowing components may cause oil
consumption:
•
Piston rings
•
Valve guides
Check for excessive crankcase blowby at the
engine crankcase breather. Refer to Systems
Operation/
Testing and Adjusting.
i02430014
Excessive Fuel Consum ption
SMCS Code: 1250-035
Probable Causes
•
Engine operation
•
Fuel leaks
•
Fuel quality
•
Engine speed/timing
•
Unit injectors
•
Air inlet and exhaust system
•
Accessory equipment
Recommended Actions
Engine Operation
Use the Caterpillar Electronic Technician (ET) to
check the “Current Totals” for excessive idle time
and/or for a high load factor which would be indicative
of poor operating habits.
Note: Engine operation may also be affected by
environmental conditions such as wind and snow.
Fuel Leaks
Check the fuel pressure during engine cranking.
Check the fuel pressure after the fuel filter. Refer
to Systems Ope
ration/Testing and Adjusting for the
correct pressure values. If the fuel pressure is low,
replace the fuel filters. If the fuel pressure is still l ow,
check the fol
lowing items: fuel transfer pump, fuel
transfer pump coupling, and fuel pressure regulating
valve.
Fuel Quality
Cold weather
adversely affects the characteristics
of the fuel. Refer to the Operation and Maintenance
Manual for information on improving the
characteris
tics of the fuel during cold weather
operation.
Engine Spee
d/Timing
Perform a speed/timing sensor calibration. Refer to
the calibra
tion procedure Troubleshooting, “Engine
Speed/Timing Sensor - Calibrate”.
Unit Inject
ors
1. Check for correct installation of the J1/P1
and J2/P2 E
lectronic Control Module (ECM)
connectors and the unit injector connectors. Refer
to the diagnostic functional test Troubleshooting,
“Electric
al Connectors - Inspect”.
2. Perform the “Injector Solenoid Test” on Cat ET in
order to de
termine if all of the injector solenoids
are being energized by the ECM.
3. Perform t
he “Cylinder Cutout Test” on Cat ET
in order to identify any injectors that might be
misfiring. Refer to the diagnostic functional test
Troubles
hooting, “Injector Solenoid Circuit - Test”.
Air Inlet and Exhaust System
1. Inspect the air filter for a restriction. If the air filter
shows signs of being plugged, clean the air filter
or replac
e the air filter.
2. Check the air inlet and exhaust system for
restric
tions and/or for leaks. Refer to Systems
Operation/Testing and Adjusting.
Accesso
ry Equipment
Check all accessory equipment for problems that
may crea
te excessive load on the engine. Repair
any damaged components or replace any damaged
components.