GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Check for an external coolant leak.
  2. Do a pressure or dye test on the cooling system. Refer to Cooling System Leak Testing .

Is the cooling system to the proper pressure?

--

Go to Step 2

Go to Step 3

2

Check for an internal coolant leak. Do a cylinder leak test. Refer to Oil Leak Diagnosis or Oil Leak Diagnosis in Engine Mechanical.

Is there an internal loss of coolant?

--

Go to Step 3

--

3

Repair the cooling system components as necessary.

Is there still a loss of coolant?

--

--

System OK