GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Check the level of the coolant in the coolant recovery reservoir or surge tank. Refer to Cooling System Draining and Filling .
  2. Add engine coolant as necessary.

Does the engine reach normal operating temperature now?

--

System OK

Go to Step 2

2

  1. Check for a blockage in the coolant passages.
  2. Flush the cooling system or flow check the radiator. Refer to Flushing .

Does the engine reach normal operating temperature now?

--

System OK

Go to Step 3

3

  1. Check to see if the correct type of thermostat was installed.
  2. Check if the thermostat is stuck in the open position. Refer to Thermostat Diagnosis .
  3. If necessary, replace the thermostat. Refer to Engine Coolant Thermostat Replacement .

Does the engine reach normal operating temperature?

--

System OK

--