Engine Overheating

Step	Action	Value(s)	Yes	No
DEFINITION: The engine temperature lamp comes on and stays on, the temperature gauge shows hot or coolant overflows from the coolant recovery reservoir onto the ground while the engine is running.
1	Check for a loss of coolant. Has there been a loss of coolant?	-	Go to Step 2	Go to Step 3
2	Refer to Loss of Coolant . Does the engine still overheat?	-	Go to Step 3	System OK
3	Check for a loss of system pressure. Use the J 24460-01 Cooling System Pressure Tester. See Special Tools . Has there been a loss of system pressure?	-	Go to Step 4	Go to Step 5
4	Correct the system pressure. Does the engine still overheat?	-	Go to Step 5	System OK
5	Check for low coolant protection. Make sure that the solution is at the specified temperature. Is there low coolant protection?	-37°C (-34°F)	Go to Step 6	Go to Step 7
6	Correct as necessary. Does the engine still overheat?	-	Go to Step 7	System OK
7	Check the accessory drive belt tension. Check the tensioner. Refer to Drive Belt Tensioner Diagnosis . Is the tensioner working properly and the tension correct?	-	Go to Step 9	Go to Step 8
8	Replace the tensioner. Refer to Drive Belt Tensioner Diagnosis . Does the engine still overheat?	-	Go to Step 9	System OK
9	Check to see if the timing is retarded by a malfunctioning powertrain control module (PCM). Is the timing retarded by a malfunctioning PCM?	-	Go to Step 10	Go to Step 11
10	Correct as necessary. Does the engine still overheat?	-	Go to Step 11	System OK
11	Check to see if any of the radiator fins are obstructed. Are any of radiator fins obstructed?	-	Go to Step 12	Go to Step 13
12	Remove or relocate any add-on parts that block air to the radiator. Remove any debris from the radiator fins. Does the engine still overheat?	-	Go to Step 13	System OK
13	Check to see if any of the cooling system passages are blocked by rust or scale. Are any of the cooling system passages blocked by rust or scale?	-	Go to Step 14	Go to Step 15
14	Drain the cooling system. Refer to Cooling System Draining and Filling (LY7 GE 47716 Fill) or Cooling System Draining and Filling (LNJ GE 47716 Fill) or Cooling System Draining and Filling (LNJ Static Fill) or Cooling System Draining and Filling (LY7 Static Fill) . Flush the cooling system. Refer to Coolant System Flushing . Repair as necessary. Does the engine still overheat?	-	Go to Step 15	System OK
15	Check for a pinched or kinked coolant recovery reservoir hose. Is the surge tank hose pinched or kinked?	-	Go to Step 16	Go to Step 17
16	Replace or reroute the hose as necessary. Refer to Radiator Surge Tank Inlet Hose/Pipe Replacement (LNJ) or Radiator Surge Tank Inlet Hose/Pipe Replacement (LY7) . Does the engine still overheat?	-	Go to Step 17	System OK
17	Check for an inoperative cooling fan. Refer to Cooling Fan Inoperative (3.6L) or Cooling Fan Inoperative (3.4L) . Are there any inoperative cooling fans?	-	Go to Step 18	Go to Step 19
18	Repair or replace the electric cooling fans as necessary. Refer to Engine Coolant Fan Motor Replacement . Does the engine still overheat?	-	Go to Step 19	System OK
19	Check for a loose, damaged, and/or missing deflector. Are there any loose, damaged, or missing deflectors?	-	Go to Step 20	Go to Step 21
20	Replace the deflectors. Does the engine still overheat?	-	Go to Step 21	System OK
21	Check to see if the thermostat is stuck in the closed position. Is the thermostat stuck in the closed position?	-	Go to Step 22	Go to Step 23
22	Replace the thermostat. Refer to Engine Coolant Thermostat Replacement (LY7) or Engine Coolant Thermostat Replacement (LNJ) . Does the engine still overheat?	-	Go to Step 23	System OK
23	Check for a faulty coolant pump. Is the coolant pump faulty?	-	Go to Step 24	Go to Step 25
24	Replace the water pump. Refer to Water Pump Replacement (RPO LNJ) or Water Pump Replacement (RPO LY7) . Does the engine still overheat?	-	Go to Step 25	System OK
25	Check for an incorrect radiator. Is the radiator correct?	-	Go to Step 26	-
26	Install the correct radiator. Refer to Radiator Replacement . Does the engine still overheat?	-	-	System OK