roubleshooting Symptoms Charts
B3.9 and B5.9 Series Engines
Section TS - Troubleshooting Symptoms
Coolant Temperature is Above Normal Sudden Overheat
This is symptom tree T023.
Inspect the engine and cooling system for
Coolant level is below specification
external coolant leaks. Repair if necessary.
Add coolant. Refer to Procedure 008-018.
an drive belt is loose, tight, or not in align-
Check the fan drive belt. Refer to Procedure
Check or replace the temperature gauge. Refer
emperature gauge malfunction
to the OEM service manual.
Check and repair fan shroud, shuttters,
irflow to the radiator is restricted (nonmarine
shutterstat, sensor, fan clutch, and viscous fan
as required. Refer to the OEM sevice manual.
ooling system hose is collapsed, restricted, or
Inspect the radiator hoses. Refer to Procedure
Check the thermostat for the correct part
number and for correct operation. Refer to
hermostat is not correct or is malfunctioning
Check the water pump for correct operation.
Replace the water pump if necessary. Refer to
ater pump is malfunctioning
Check the vent lines and the fill line for correct
ill line or vent lines are restricted, obstructed,
routing and for restriction. Refer to OEM
or not routed correctly
cooling system. Refer to Procedure 008-019.