Inspect for a missing or damaged radiator upper baffle and/or center air deflector.

Is the baffle or deflector missing or damaged?

Go to Step 8

Go to Step 2

Inspect for a loss of coolant.

Is there a loss of coolant?

Go to Step 3

Go to Step 4

Fill the system to the specified level. Refer to Loss of Coolant .

Does the engine overheat?

Go to Step 4

System OK

Inspect for low coolant protection. Refer to Coolant Concentration Testing .

Is the coolant to the correct concentration?

Go to Step 5

Go to Step 8

Inspect for a loss of system pressure. Refer to Cooling System Leak Testing .

Is there a loss of system pressure?

Go to Step 8

Go to Step 6

Inspect for a faulty engine coolant temperature (ECT) sensor. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls.

Is the sensor operating properly?

Go to Step 7

Go to Step 8

Inspect for a cracked coolant surge tank or a leaking hose. Refer to Loss of Coolant .

Is the surge tank cracked or is the hose leaking?

Go to Step 8

Go to Step 3

Repair or install new parts as necessary, then retest.

Does the engine overheat?

Go to Step 9

System OK

Inspect for incorrect drive belt tension. Refer to Drive Belt Tensioner Replacement - Accessory in Engine Mechanical.

Is the belt tension correct?

Go to Step 10

Go to Step 8

Inspect for a damaged water pump driveshaft.

Is the water pump driveshaft damaged or is the seal leaking?

Go to Step 8

Go to Step 11

Inspect for obstructed radiator air flow or bent radiator fins.

Is the radiator air flow obstructed?

Go to Step 8

Go to Step 12

Inspect for blocked cooling system passages.

Are the cooling system passages blocked?

Go to Step 8

Go to Step 13

Inspect for improper direction or inoperative cooling fans. Refer to Cooling Fan Motor Replacement - Electric .

Are the cooling fans and the motors operating correctly?

Go to Step 14

Go to Step 8

Inspect the thermostat. Refer to Thermostat Diagnosis .

Is the thermostat stuck in the closed position?

Go to Step 15

Go to Step 16

Replace the thermostat. Refer to Engine Coolant Thermostat Replacement .

Does the engine overheat?

Go to Step 16

System OK

Inspect the radiator cooling capacity.

Is the proper sized radiator being used on the vehicle?

Go to Step 3

Go to Step 17

Consult the current parts catalog and replace the radiator. Refer to Radiator Replacement .

Is the repair complete?

System OK