GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Make a visual check of the cooling system.
  2. Check the ground under the vehicle.

Is there coolant visible on the ground?

--

Go to Step 3

Go to Step 2

2

Check the radiator for stains and wetness.

Are there any stains or is there any wetness on the radiator?

--

Go to Step 3

Go to Step 4

3

Repair as necessary.

Is there still a coolant loss?

--

Go to Step 4

System OK

4

Check the coolant hoses for stains and wetness.

Are there any stains or is there any wetness on the coolant hoses?

--

Go to Step 5

Go to Step 6

5

Repair as necessary.

Is there still a loss of coolant?

--

Go to Step 6

System OK

6

Check the coolant pump for stains and wetness.

Are there any stains or is there any wetness on the coolant pump?

--

Go to Step 7

Go to Step 8

7

Repair as necessary.

Is there still a loss of coolant?

--

Go to Step 8

System OK

8

Check the coolant recovery reservoir for leakage.

Does the coolant overflow from the reservoir with the engine off?

--

Go to Step 9

System OK

9

Check the radiator cap for proper pressure retention. Refer to Cooling System Leak Testing .

Does the radiator cap maintain the correct pressure?

103 kPa (15 psi)

Go to Step 10

Go to Step 11

10

Check the temperature reading of the thermostat. Refer to Thermostat Diagnosis .

Is the temperature too high?

--

Go to Engine Overheating .

Go to Step 12

11

Replace the radiator cap. Refer to Radiator Filler Cap Assembly .

Is there still a coolant loss?

--

Go to Step 12

System OK

12

Check the coolant concentration.

Is the coolant concentration too low?

--

Go to Step 13

System OK

13

Replace the coolant with the proper mixture of DEX-COOLâ„¢. Refer to

Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

.

Is there still a coolant loss?

--

--

System OK