FixVault

Engine Overheating

Step Action Yes No
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.
1 Check for a loss of coolant. Refer to Loss of Coolant 
Is there a loss of coolant?
Go to Step 2  Go to Step 3 
2 Fill the system to the specified level. Refer to Cooling System Draining and Filling (Static without HP9) Cooling System Draining and Filling (GE 47716 without HP9) Cooling System Draining and Filling (Static LTG with HP9) Cooling System Draining and Filling (GE 47716 LTG with HP9) 
Does the engine still overheat?
Go to Step 3  System OK
3 Check for kinked or pinched surge tank hoses, especially at the radiator.
Are any surge tank hoses kinked or pinched?
Go to Step 4  Go to Step 5 
4
  1. Relieve any kinks by rerouting the hoses.
  2. Replace the hoses, if necessary.
Does the engine still overheat?
Go to Step 5  System OK
5 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 Step 6  Go to Step 7 
6 Repair or replace any loose, missing or damaged radiator air seals or deflectors.
Does the engine still overheat?
Go to Step 7  System OK
7 Check the coolant concentration.
Does the coolant concentration test correctly?
Go to Step 9  Go to Step 8 
8 Replace the coolant, if necessary. Refer to Cooling System Draining and Filling (Static without HP9) Cooling System Draining and Filling (GE 47716 without HP9) Cooling System Draining and Filling (Static LTG with HP9) Cooling System Draining and Filling (GE 47716 LTG with HP9) .
Does the engine still overheat?
Go to Step 9  System OK
9
NOTE: Use the correct pressure cap.
Check the system for loss of pressure. Pressure Cap Testing Is there a loss of pressure?
Go to Step 10  Go to Step 11 
10 Repair any leaks, as necessary.
Does the engine still overheat?
Go to Step 11  System OK
11 Check for a faulty engine coolant temperature sensor.
Is the engine coolant temperature sensor faulty?
Go to Step 12  Go to Step 13 
12 Replace the engine coolant temperature sensor. Engine Coolant Temperature Sensor Replacement or Engine Coolant Temperature Sensor Replacement
Does the engine still overheat?
Go to Step 13  System OK
13 Check the radiator for any air flow obstructions or bent fins.
Is there any airflow obstruction or bent fins?
Go to Step 14  Go to Step 15 
14
  1. Remove or relocate add-on parts that block air flow to the radiator.
  2. Clean any debris from the radiator core.
Does the engine still overheat?
Go to Step 15  System OK
15 Check for any blocked cooling system passages.
Are there any blocked cooling system passages?
Go to Step 16  Go to Step 17 
16
  1. Remove any obstruction.
  2. Flush the cooling system, as required. Refer to Flushing (LGW LTG without HP9) 
  3. Refill the coolant. Refer to Cooling System Draining and Filling (Static without HP9) Cooling System Draining and Filling (GE 47716 without HP9) Cooling System Draining and Filling (Static LTG with HP9) Cooling System Draining and Filling (GE 47716 LTG with HP9) 
Does the engine still overheat?
Go to Step 17  System OK
17 Check for an inoperative cooling fan.
Is the cooling fan inoperative?
Go to Step 18  Go to Step 19 
18 Replace the cooling fan shroud. Refer to Engine Coolant Fan Shroud Replacement (LGW LGX LTG) 
Does the engine still overheat?
Go to Step 19  System OK
19 Check for a thermostat that is stuck closed.
Is the thermostat stuck closed?
Go to Step 20  Go to Step 21 
20 Replace the thermostat. Refer to Engine Coolant Thermostat Housing Replacement (LGW, LGX)  and/or Engine Coolant Thermostat Housing Replacement (LTG) 
Does the engine still overheat?
Go to Step 21  System OK
21 Check for a faulty water pump. The impeller blades may be eroded or broken.
Is the water pump faulty?
Go to Step 22  -
22 Replace the water pump. Refer to Water Pump Replacement (LGW, LGX)  and/or Water Pump Replacement (LTG) 
Does the engine still overheat?
- System OK