Temperature Sensor Validation Test - Navistar International DT 466 Diagnostic/Troubleshooting Manual

120
• If oil is contaminated with coolant, go to
"Coolant in Lube Oil" (page 109) in this
section.
• If no leaks are found, do step 3.
WARNING: To avoid serious personal
injury, possible death and damage to the
engine:
• Always allow the engine to cool for 15
minutes.
• Wrap a thick cloth around the cap.
• Loosen cap slowly a quarter to half turn.
• Pause for a moment to avoid water or
steam scalding.
• Continue to turn the cap and remove.
• Never add cold coolant to a hot engine.
This can result in a cracked cylinder head
or crankcase.
• Never use water as a coolant substitute.
3. Fill cooling system to the maximum coolant level
mark.
Figure 136 Coolant crossover pipe drain valve
4. Start the engine.
5. Purge all air out of system by opening the coolant
crossover pipe drain valve. Close the port when
coolant appears.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
4 ENGINE SYMPTOMS DIAGNOSTICS
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
WARNING: To avoid serious personal
injury, possible death, or damage to the
engine or vehicle, use extreme caution when
purging air out of the cooling system.
6. Test again for over-temperature condition
• If the engine is not running over-temperature,
do step 7.
• If the engine continues overheating, do step
9.
7. Install radiator pressure
appropriate adapter.
8. Pressurize the cooling system to 96 kPa (14 psi)
• If coolant is leaking externally, identify the leak
and repair.
• If coolant is not leaking externally, but the
pressure is dropping, see "Coolant Leak to
Exhaust" (page 117) and "Coolant in Lube Oil"
(page 109) in this section.
9. Inspect the condition of the following items:
cooling fan blade, shroud, accessory drive belt,
accessory drive belt tensioner, cooling fan drive
clutch, operation of electric or air fan, and radiator.
CAUTION: To avoid radiator damage, when using
high pressure washer, be careful not to damage
radiator fins with wand.
• If vehicle is new or recently repaired, verify
the correct part number for any component
related to the cooling system.
• If the radiator cooling fins are blocked due to a
build-up of dirt or debris, use a power washer
to clean blockage from radiator fins or any
debris on the cooling fan and fan drive clutch.
• If no problems
"Temperature Electrical System Test" (page
120) in this section.

Temperature Sensor Validation Test

1. Install EST and check for active and inactive
DTCs related to engine coolant over-temp
conditions.
• If any DTCs remain relating to coolant
over-temp condition, correct DTC before
continuing.
tester with the
are identified, go to