Table 4-1.--Diesel Engine Troubleshooting Chart--Continued
TROUBLE
PROBABLE CAUSE
REMEDY
Abnormal engine temperature:
High temperature.
Insufficient heat transfer.
Test cooling system temperature.
Clean cooling system by flushing.
Thermostat not opening.
Test thermostat.
Coolant circulation inadequate.
Check coolant level.
Air circulation through radiator in- Replace broken fan belt.
adequate.
Clean fan and radiator.
Loss of coolant.
Replace broken radiator hose.
Correct water pump gasket leak.
Torque head bolts.
Replace engine. (Refer to QEC in-
structions.)
Low temperature.
Thermostat not closing.
Replace thermostat.
Q4-35.
When testing a GM diesel engine injector, you
of the most common problems, the probable causes of
must first perform which of the following
the problems, and the remedies for correcting them.
tasks?
In-depth, up-to-date troubleshooting charts are in-
cluded in the applicable maintenance manuals for your
1.
Loosen the fuel line to the injector
model engines.
2.
Remove the valve cover
3.
Depress the injector with a screwdriver
Q4-34.
Which of the following reasons is one of the
4.
Remove all the injectors and test them
main causes for difficulty in starting a diesel
with an injector tester
engine?
Q4-36.
Which of the following discrepancies is the
1.
The injectors are clogged
probable cause of an abnormal operation of a
2.
The fuel filter is clogged
diesel engine during acceleration?
3.
There is air trapped in the fuel system
4.
The battery voltage is low
1.
Improper ignition timing
2.
Clogged fuel injector
3.
Low fuel in the unit
4.
Intake valve time is incorrect
4-47
