For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Inspect the following conditions:

• | The level of the coolant

• | The mixture of the coolant

Is the coolant mixed properly and at the proper level?

Go to Step 3

Go to Step 2

2 | Add the coolant. Does the engine still overheat? | Go to Step 3 | System OK
3 | Inspect the generator/coolant pump drive belt. Is the generator/coolant pump drive belt loose or missing? | Go to Step 4 | Go to Step 5
4 | Adjust or replace the belt. Does the engine still overheat? | Go to Step 5 | System OK
5 | Inspect the front of the radiator for the following items:

• | Dirt

• | Leaves

• | Insects

Is the front of the radiator dirty?

Go to Step 6

Go to Step 7

6 | Clean the front of the radiator. Does the engine still overheat? | Go to Step 7 | System OK
7 | Inspect the following components for leaks:

• | The hoses

• | The coolant pump

• | The heater

• | The thermostat housing

• | The radiator

• | The head gasket

Is leakage present?

Go to Step 8

Go to Step 9

8 | Repair the leaks as necessary. Does the engine still overheat? | Go to Step 9 | System OK
9 | Inspect the thermostat. Is the thermostat faulty? | Go to Step 10 | Go to Step 11
10 | Replace the thermostat. Does the engine still overheat? | Go to Step 11 | System OK
11 | Inspect the cylinder head torque. Is the cylinder head torque correct? | Go to Step 13 | Go to Step 12
12 |

1. Re-tighten the cylinder head bolts to specification.
2. Replace the cylinder head gasket if required.

Does the engine still overheat?

Go to Step 13

System OK

13 | Inspect the intake manifold. Is the intake manifold leaking? | Go to Step 14 | Go to Step 15
14 | Complete the following actions as necessary in order to correct the leak:

• | Repair the intake manifold.

• | Replace the components.

Does the engine still overheat?

Go to Step 15

System OK

15 | Inspect the cylinder head gasket. Is the cylinder head gasket leaking? | Go to Step 16 | Go to Step 17
16 | Repair or replace the components as necessary in order to correct the leak. Does the engine still overheat? | Go to Step 17 | System OK
17 | Inspect the cylinder block plug. Is the cylinder block plug leaking? | Go to Step 18 | Go to Step 19
18 | Repair or replace the components as necessary in order to correct the leak. Does the engine still overheat? | Go to Step 19 | System OK
19 | Inspect the heater core. Is the heater core leaking? | Go to Step 20 | Go to Step 21
20 | Repair or replace the components as necessary in order to correct the leak. Does the engine still overheat? | Go to Step 21 | System OK
21 | Inspect the coolant valve, if equipped. Is the coolant valve leaking? | Go to Step 22 | --
22 | Repair or replace the components as necessary in order to correct the leak. Does the engine still overheat? | -- | System OK