Engine Overheating (LM2)

Engine Overheating

	Step	Action	Yes	No
	DEFINITION: The engine temperature lamp comes on and stays on, or temperature gauge shows hot, or a Diagnostic Trouble Code (DTC) is set, or coolant overflows from the surge tank onto the ground while the engine is running.
	1	Check for any Diagnostic Trouble Codes (DTC). Are there any Diagnostic Trouble Codes (DTC) present?	Refer to the appropriate Diagnostic Trouble Codes (DTC). Diagnostic Trouble Code (DTC) List - Vehicle	Go to Step 2
	2	Check for a loss of coolant. Loss of Coolant Is there a loss of coolant?	Go to Step 3	Go to Step 4
	3	Fill the system to the specified level. Cooling System Draining and Filling Does the engine still overheat?	Go to Step 4	System OK
	4	Check for kinked or pinched surge tank hoses, especially at the radiator. Are any surge tank hoses kinked or pinched?	Go to Step 5	Go to Step 6
	5	1. Relieve any kinks by rerouting the hoses. 2. Replace the hoses, if necessary. Does the engine still overheat?	Go to Step 6	System OK
	6	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 7	Go to Step 8
	7	Repair or replace any loose, missing, or damaged radiator air seals or deflectors. Does the engine still overheat?	Go to Step 8	System OK
	8	Check the coolant concentration. Does the coolant concentration test correctly?	Go to Step 10	Go to Step 9
	9	Replace the coolant, if necessary. Cooling System	Go to Step 10	System OK

Step	Action	Yes	No
	Does the engine still overheat?
10	Note: Use the correct radiator surge tank cap. Check the system for loss of pressure. Radiator Surge Tank Cap Testing Is there a loss of pressure?	Go to Step 11	Go to Step 12
11	Repair any leaks, as necessary. Does the engine still overheat?	Go to Step 12	System OK
12	Check the radiator for any air flow obstructions or bent fins. Is there any airflow obstruction or bent fins?	Go to Step 13	Go to Step 14
13	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 14	System OK
14	Check for any blocked cooling system passages. Are there any blocked cooling system passages?	Go to Step 15	Go to Step 16
15	1. Remove any obstruction. 2. Flush the cooling system, as required. Flushing 3. Refill the coolant. Cooling System Draining and Filling Does the engine still overheat?	Go to Step 16	System OK
16	Check for an inoperative cooling fan. Is the cooling fan inoperative?	Go to Step 17	Go to Step 18
17	Replace the cooling fan. Engine Cooling Fan Motor Replacement Does the engine still overheat?	Go to Step 18	System OK
18	Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty?	Go to Step 19	—
19	Replace the water pump. Water Pump Replacement Does the engine still overheat?	—	System OK