GM Service Manual Online
For 1990-2009 cars only
Table 1: Engine Overheats
Table 2: Radiator Loose

Engine Overheats

Step

Action

Value(s)

Yes

No

1

Check for an obstructed cooling area around the radiator.

Is air to the radiator being blocked?

--

Go to Step 2

Go to Step 3

2

Remove or relocate any add-on parts that may block air to the radiator

Does the engine still overheat?

--

Go to Step 3

System OK

3

Check to see if the radiator fins are plugged.

Are any radiator fins plugged?

--

Go to Step 4

Go to Step 5

4

Remove any debris from the radiator fins.

Does the engine still overheat?

--

Go to Step 5

System OK

5

Check for bent fins on the radiator.

Are there any bent fins on the radiator?

--

Go to Step 6

Go to Step 7

6

Repair the bent fins as necessary.

Does the engine still overheat?

--

Go to Step 7

System OK

7

  1. Check for a leaking radiator.
  2. Leak test the radiator. Refer to Radiator Leak Testing .

Is the radiator leaking?

--

Go to Step 8

System OK

8

Replace the radiator as necessary. Refer to Radiator Replacement .

Does the engine still overheat?

--

--

System OK

Radiator Loose

Step

Action

Value(s)

Yes

No

1

Make sure the fasteners that support the radiator are tightened to the proper specification.

Are the fasteners tightened to specification?

--

Go to Step 3

Go to Step 2

2

Tighten the fasteners to specifications. Refer to Fastener Tightening Specifications .

Is the radiator still loose?

--

Go to Step 3

System OK

3

Check for any missing or damaged radiator insulators.

Are there any damaged or missing radiator insulators?

--

Go to Step 4

System OK

4

Replace the radiator insulators as necessary.

Is the radiator still loose?

--

--

System OK