Engine Overheating

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

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. Cooling System Draining and Filling (Static) Cooling System Draining and Filling (GE 47716) 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	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. Refer to Cooling System Draining and Filling (Static) Cooling System Draining and Filling (GE 47716) . 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 (LF4)Engine Coolant Temperature Sensor Replacement (LGX) , 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	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 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	Remove any obstruction. Flush the cooling system, as required. Flushing Refill the coolant. Cooling System Draining and Filling (Static) Cooling System Draining and Filling (GE 47716) 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. Engine Coolant Fan Shroud Replacement (LTG without V03) Engine Coolant Fan Shroud Replacement (LTG with VO3) Engine Coolant Fan Shroud Replacement (LGX) Engine Coolant Fan Shroud Replacement (LF4) 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. Engine Coolant Thermostat Housing Replacement (LCV) Engine Coolant Thermostat Housing Replacement (LGX) Engine Coolant Thermostat Housing Replacement (LF4) 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. Water Pump Replacement (LF4) Water Pump Replacement (LTG) Water Pump Replacement (LGX) Does the engine still overheat?	Go to Step 23	System OK
23	If equipped, check for a restriction at the heater water auxiliary pump or a faulty heater water auxiliary pump. Is there a restriction or was there a faulty auxiliary coolant pump?	Go to Step 24	System OK
24	Replace the heater water auxiliary pump. Heater Water Auxiliary Pump Replacement (LTG with KL9) Does the engine still overheat?	-	System OK