PRE-RELEASE
Engine Overheating
| Engine Overheating |
| Step | Action | Yes | No | |||||||||
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DEFINITION: The engine temperature lamp comes on and stays on, or temperature gauge shows hot, or coolant overflows from the surge tank onto the ground while the engine is running.
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1
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Check for a loss of coolant. Refer to
Loss of Coolant
.
Is there a loss of coolant? |
Go to
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Go to
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2
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Fill the system to the specified level.
Does the engine still overheat? |
Go to
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System OK
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3
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Check for kinked or pinched surge tank hoses, especially at the radiator.
Are any surge tank hoses kinked or pinched? |
Go to
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Go to
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4
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Does the engine still overheat? |
Go to
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System OK
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5
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Check for loose, missing, or damaged radiator air seals or deflectors.
Are there any loose, missing, or damaged radiator air seals or deflectors? |
Go to
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Go to
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6
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Repair or replace any loose, missing, or damaged radiator air seals or deflectors.
Does the engine still overheat? |
Go to
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System OK
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7
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Check the coolant concentration.
Does the coolant concentration test correctly? |
Go to
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Go to
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8
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Replace the coolant, if necessary.
Does the engine still overheat? |
Go to
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System OK
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9
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Check the system for loss of pressure. Refer to Pressure Cap Testing . Is there a loss of pressure? |
Go to
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Go to
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10
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Repair any leaks, as necessary.
Does the engine still overheat? |
Go to
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System OK
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11
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Check for a faulty engine coolant temperature sensor.
Is the engine coolant temperature sensor faulty? |
Go to
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Go to
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12
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Replace the engine coolant temperature sensor. Refer to:
Does the engine still overheat? |
Go to
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System OK
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13
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Check the radiator for any air flow obstructions or bent fins.
Is there any airflow obstruction or bent fins? |
Go to
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Go to
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14
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Does the engine still overheat? |
Go to
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System OK
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15
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Check for any blocked cooling system passages.
Are there any blocked cooling system passages? |
Go to
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Go to
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16
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Does the engine still overheat? |
Go to
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System OK
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17
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Check for an inoperative cooling fan.
Is the cooling fan inoperative? |
Go to
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Go to
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18
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Replace the cooling fan. Refer to
Engine Coolant Fan Motor Replacement (Diesel)
Engine Coolant Fan Motor Replacement (LAU/A28NER)
Does the engine still overheat? |
Go to
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System OK
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19
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Check for a thermostat that is stuck closed.
Is the thermostat stuck closed? |
Go to
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Go to
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20
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Replace the thermostat. Refer to
Engine Coolant Thermostat Replacement (Diesel)
Engine Coolant Thermostat Replacement (LLU/A16LET)
Engine Coolant Thermostat Replacement (LHU/A20NFT)
Does the engine still overheat? |
Go to
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System OK
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21
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Check for a faulty water pump. The impeller blades may be eroded or broken.
Is the water pump faulty? |
Go to
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-
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22
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Replace the water pump. Refer to
Water Pump Replacement (Diesel)
Water Pump Replacement (LAU/A28NER)
Water Pump Replacement (LHU/A20NFT)
.
Does the engine still overheat? |
-
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System OK
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