GM Service Manual Online
For 1990-2009 cars only

Engine Overheats

Step

Action

Value

Yes

No

1

Check for an obstructed air flow through the radiator.

Is the air flow path clear?

--

Go to Step 3

Go to Step 2

2

Remove or relocate added on parts that may block the air flow through the radiator.

Is the air flow path clear now?

--

System OK

--

3

Check for plugged radiator fins.

Are the radiator fins plugged?

--

Go to Step 4

Go to Step 5

4

Remove any debris (bugs, leaves, etc.) from the radiator fins.

Are the fins clear now?

--

System OK

--

5

Check the radiator for leaks, refer to Radiator Leak Testing (On and Off Vehicle)

Is the radiator leaking?

--

Go to Step 6

Go to Step 7

6

Repair or replace the radiator as necessary.

Is the repair complete?

--

System OK

--

7

Check the radiator for bent fins.

Are the fins bent?

--

Go to Step 8

--

8

Repair the bent fins or replace the radiator core.

Is the repair complete?

--

System OK

--