Check the coolant level.

Is the coolant level below the add mark?

Go to Step 2

Go to Step 3

1. Add coolant as necessary.
2. Perform a cooling system pressure test.

Is the repair complete?

System OK

--

Check for a stuck open, missing, or wrong type of coolant thermostat. Refer to Thermostat Diagnosis .

Is the thermostat operating properly?

System OK

Go to Step 4

Install the correct replacement thermostat. Refer to Engine Coolant Thermostat Replacement .

Is the repair complete?

System OK

--