TM 5-2420-230-24-2
roubleshooting Symptoms Charts
B3.9 and B5.9 Series Engines
Page TS-18
Section TS - Troubleshooting Symptoms
Coolant Temperature Above Normal Gradual Overheat (Continued)
Cause
Correction
Inspect the shroud and the recirculation
baffles. Repair, replace, or install, if necessary.
Fan shroud is damaged or missing, or the air
.......
Refer to Procedure 008-038 and the OEM
recirculation baffles are damaged or missing
service manual.
OK
C
ooling system pressure cap is not correct, is
Inspect the pressure cap. Refer to Procedure
.......
malfunctioning, or has a low-pressure rating
008-047.
OK
C
Verify the concentration of antifreeze in the
coolant. Add antifreeze or water to correct the
oolant mixture of antifreeze and water is not
.......
concentration. Refer to Cooling System
correct
Specifications in Section 8.
OK
T
Check or replace the temperature gauge. Refer
emperature gauge malfunction
.......
to the OEM service manual.
OK
T
Check the thermostat for the correct part
number and for correct operation. Refer to
Procedure 008-013. Make sure thermostat is
hermostat is not correct or is malfunctioning
.......
vented properly. Refer to Application Engineer-
ing Bulletin, AEB 90.24.
OK
A
Check for air or combustion gases in the
ir or combustion gases are entering the
.......
cooling system. Refer to Procedure 008-019.
cooling system
Check fill rate to see if it not being exceeded.
OK
S
Check for inlet restriction or aeration. Check
system discharge or outlet pressure. Check the
ea water pump is malfunctioning (marine
.......
sea water pump impeller for damage. Refer to
engines only)
Procedure 008-057.
OK
P
lugged or restricted heat exchanger (marine
Clean the heat exchanger, both sea water and
.......
coolant passages. Refer to Procedure 008-053.
engines only)
OK
T
(Continued)
L-602
