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. 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. Does the engine still overheat?	Go to Step 3	System OK
3	Check for kinked or pinched surge tank hoses, especially at the radiator. Check coolant hoses for a coolant flow restriction due to foreign material/objects. Are any surge tank hoses kinked, pinched or flow restricted?	Go to Step 4	Go to Step 5
4	Relieve any kinks by rerouting the hoses. 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. 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 Does the engine still overheat?	Go to Step 13	System OK
13	Check the bleed hole in the bypass valve of the water outlet adapter. If the bleed hole is clogged with debris, unclog the bleed hole by cleaning with coolant. If the bleed hole is still clogged, replace the water outlet adapter. Water Outlet Replacement Does the engine still overheat?	Go to Step 14	System OK
14	Check the radiator for any air flow obstructions or bent fins. Is there any airflow obstruction or bent fins?	Go to Step 15	Go to Step 16
15	Remove or relocate add-on parts that block air flow to the radiator. Clean any debris from the radiator core. Does the engine still overheat?	Go to Step 16	System OK
16	Check for any blocked cooling system passages including inoperative or obstructed in-line auxiliary electric pumps. Are there any blocked cooling system passages?	Go to Step 17	Go to Step 18
17	Remove any obstruction. Flush the cooling system, as required. Refill the coolant. Does the engine still overheat?	Go to Step 18	System OK
18	Check for an inoperative cooling fan. Is the cooling fan inoperative?	Go to Step 19	Go to Step 20
19	Replace the cooling fan. Engine Coolant Fan Replacement Does the engine still overheat?	Go to Step 20	System OK
20	Check for a thermostat that is stuck closed. Thermostat Diagnosis Is the thermostat stuck closed?	Go to Step 21	Go to Step 22
21	Replace the thermostat housing. Engine Coolant Thermostat Housing Replacement Does the engine still overheat?	Go to Step 22	System OK
22	Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty?	Go to Step 23	-
23	Replace the water pump. Water Pump Replacement Does the engine still overheat?	Go to Step 24	System OK
24	If equipped, check for a restriction at the auxiliary water pump or a faulty auxiliary water pump. Is there a restriction or a faulty auxiliary water pump?	Go to Step 25	System OK
25	Replace the auxiliary water pump. Auxiliary Water Pump Replacement Does the engine still overheat?	-	System OK