Step  | Action  | Value(s)  | Yes  | No  | 
|---|---|---|---|---|
DEFINITION: The engine temperature lamp comes on and stays on, or the temperature gage shows hot, or coolant overflows from the surge tank onto the ground while the engine is running.  | ||||
1  | Check for low coolant. Is the coolant low?  | --  | 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 a missing or damaged radiator upper air deflector, baffle, or center air deflector. Are there any missing or damaged deflectors or baffles?  | --  | Go to Step 4  | Go to Step 5  | 
4  | Repair or replace any deflectors or baffles as necessary. Does the engine still overheat?  | --  | Go to Step 5  | System OK  | 
5  | Check the coolant concentration. Is the coolant concentration adequate?  | --  | Go to Step 7  | Go to Step 6  | 
6  | Correct the coolant concentration as necessary. Does the engine still overheat?  | --  | Go to Step 7  | System OK  | 
7  | Pressure test the cooling system. Does the cooling system maintain the correct pressure?  | 103 kPa (15 psi)  | Go to Step 9  | Go to Step 8  | 
8  | Refer to Loss of Coolant . Does the engine still overheat?  | --  | Go to Step 9  | System OK  | 
9  | Check for a pinched or kinked radiator surge tank hose. Is the surge tank hose kinked or damaged?  | --  | Go to Step 10  | Go to Step 11  | 
10  | Reroute or replace the hose as necessary. Does the engine still overheat?  | --  | Go to Step 11  | System OK  | 
11  | Check the water pump belt tension. Is the tensioner working properly?  | --  | Go to Step 13  | Go to Step 12  | 
12  | Replace the tensioner as necessary. Does the engine still overheat?  | --  | Go to Step 13  | System OK  | 
13  | Check for an obstructed radiator air flow or bent fins. Are any radiator fins bent or is air flow to the radiator being obstructed?  | --  | Go to Step 14  | Go to Step 15  | 
14  | Remove or relocate add on parts that block air flow to the radiator. Does the engine still overheat?  | --  | Go to Step 15  | System OK  | 
15  | Check for a blockage in the cooling system passages. Are the cooling system passages blocked?  | --  | Go to Step 16  | Go to Step 17  | 
16  | 
 Does the engine still overheat?  | --  | Go to Step 17  | System OK  | 
17  | Check for an inoperative cooling fan. Are the cooling fans inoperative?  | --  | Go to Step 18  | Go to Step 19  | 
18  | Repair or replace the cooling fan as necessary. Refer to Engine Coolant Fan Motor Replacement . Does the engine still overheat?  | --  | Go to Step 19  | System OK  | 
19  | Check if the thermostat is stuck in the closed position. Is the thermostat sticking or stuck in the closed position?  | --  | Go to Step 20  | Go to Step 21  | 
20  | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat?  | --  | Go to Step 21  | System OK  | 
21  | Check for a faulty water pump. Is the water pump faulty?  | --  | Go to Step 22  | --  | 
22  | Replace the water pump. Refer to Water Pump Replacement . Does the engine still overheat?  | --  | --  | System OK  |