PLATE 3079862 - Caterpillar

Probable Causes
High ambient air temperature
High intake air restriction and/or high altitude
Intake air from a heated area
Insufficient ambient air flow over the engine
Insufficient flow of cooling water through the aftercooler (if equipped)
Insufficient flow of air through the aftercooler (if equipped)Recommended Repairs
High Ambient Air Temperature
Determine if the ambient air temperature is within the design specifications for the cooling system.Determine the cause of the high air temperature. Make corrections, when possible.Check for High Intake Air Restriction and/or High Altitude
When the pressure of the intake air is low, the turbocharger (if equipped) works harder in order to achieve the desired intake manifold pressure. This increases intake air temperature.Measure the intake manifold pressure while the engine is operating under load. For specific data, refer to the Technical Marketing Information for the engine.Intake Air Restriction
Check for plugged air filters. Check for obstructions in the air intake. Replace the air filters and/or remove the obstruction from the air intake.High Altitude
Make sure that the settings for the engine are correct for the altitude.Intake Air from a Heated Area
Ensure that the air inlet system is not receiving air from a heated area.
If necessary, relocate the air supply to the intake manifold to the outside of the engine enclosure.
Check for air leaks in the pipe between the air inlet and the inlet to the turbocharger compressor. Insufficient Ambient Air Flow over the Engine
If equipped, check the condition of the cooling fan and the drive belt.
If equipped, check that the cooling fan is operating correctly. Check for Sufficient Coolant Flow Through the Aftercooler (if equipped)
Check the temperature of the coolant at the intake to the aftercooler. Compare the reading to the regulated temperature. If the temperature is OK, check the outlet temperature of the coolant. A high temperature differential indicates an insufficient flow rate.If there is a high differential between the temperature of the coolant at the intake to the aftercooler and the temperature of the coolant at the outlet of the aftercooler, perform the following procedures:
Check the coolant circuit of the aftercooler for obstructions.
Check the pump for proper operation.
Make repairs, if necessary.Check for Sufficient Flow of Air Through the Aftercooler (if equipped)
Determine the pressure differential of the intake air across the aftercooler. For specific data, refer to the Technical Marketing Information for the engine.If the pressure differential of the air across the aftercooler does not match the specifications, clean the aftercooler.