For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Inspect for a loss of system pressure. Is there a loss of system pressure? | -- | Go to Step 2 | Go to Step 3
2 | Inspect the hoses for loose connections. Repair any loose connections. Does the engine still overheat? | -- | Go to Step 3 | System OK
3 | Inspect for low coolant protection (-37°C/-34°F). Refer to Coolant Concentration Testing . Is the coolant protection low? | -- | Go to Step 4 | Go to Step 5
4 | Test solution. Correct low coolant protection. Refer to Coolant Concentration Testing . Does the engine still overheat? | -- | Go to Step 5 | System OK
5 | Inspect the water pump belt for low tension. Is the water pump belt tension too low? | -- | Go to Step 6 | Go to Step 7
6 | Replace the water pump belt tensioner. Does the engine still overheat? | -- | Go to Step 7 | System OK
7 | Inspect for an inoperative water pump. Is the water pump inoperative? | -- | Go to Step 8 | Go to Step 9
8 | Replace the water pump. Refer to Water Pump Replacement . Does the engine still overheat? | -- | Go to Step 9 | System OK
9 | Inspect for obstructed radiator fins. Are the radiator fins obstructed? | -- | Go to Step 10 | Go to Step 11
10 | Clean the radiator fins. Does the engine still overheat? | -- | Go to Step 11 | System OK
11 | Inspect for a blocked system passage. Is the system passage blocked? | -- | Go to Step 12 | Go to Step 13
12 | Flush the system and reroute or replace the hose. Does the engine still overheat? | -- | Go to Step 13 | System OK
13 | Inspect the water pump for damage to the belt. Is the belt damaged? | -- | Go to Step 14 | Go to Step 15
14 | Replace the accessory drive belt. Does the engine still overheat? | -- | Go to Step 15 | System OK
15 | Inspect for inoperative cooling fan. Is the cooling fan inoperative? | -- | Go to Step 16 | Go to Step 17
16 | Inspect and repair cooling fan. Does the engine still overheat? | -- | Go to Step 17 | System OK
17 | Inspect for restricted throttle body circuit flow. Is the throttle body circuit flow restricted? | -- | Go to Step 18 | Go to Step 19
18 | Inspect and clear the orifice and the associated hose. Does the engine still overheat? | -- | Go to Step 18 | System OK
19 | Inspect the thermostat to see if it is in a closed position. Is the thermostat in a closed position? | -- | Go to Step 20 | --
20 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat? | -- | -- | System OK