GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect for heat shields that contact the exhaust pipes when cold, AND after a warm-up.

Are the heat shields misaligned or loose?

--

Go to Step 2

Go to Step 3

2

Tighten the heat shield fasteners. Refer to Fastener Tightening Specifications

Is there still exhaust noise?

--

Go to Step 3

System OK

3

Inspect for leaks at the exhaust manifold and the exhaust pipe connections.

Are there leaks?

--

Go to Step 4

Go to Step 5

4

Tighten the leaking connections to the proper specifications. Refer to Fastener Tightening Specifications .

Is there still exhaust noise?

--

Go to Step 5

System OK

5

Inspect the muffler.

Is the muffler burned or rusted?

--

Go to Step 6

Go to Step 7

6

Replace the muffler. Refer to Muffler Replacement or Muffler Replacement .

Is there still exhaust noise?

--

Go to Step 7

System OK

7

Inspect for a burned or rusted exhaust pipe.

Is the exhaust pipe burned or rusted?

--

Go to Step 8

Go to Step 9

8

Replace the burned or rusted exhaust pipe.

Refer to Exhaust Pipe Replacement or Exhaust Pipe Replacement .

Is there still exhaust noise?

--

Go to Step 9

System OK

9

Inspect for a leak at the exhaust crossover pipe at the manifold flange.

Is there a leak?

--

Go to Step 10

Go to Step 11

10

Repair the leak.

Is there still exhaust noise?

--

Go to Step 11

System OK

11

Inspect for a cracked or broken manifold.

Is the manifold cracked or broken?

--

Go to Step 12

Go to Step 13

12

Replace the manifold.

Refer to one of the following:

Is there still exhaust noise?

--

Go to Step 13

System OK

13

Inspect for leaks between the manifold and the cylinder head.

Is there a leak?

--

Go to Step 14

System OK

14

Tighten the manifold-to-cylinder head fasteners to specifications.

Refer to Fastener Tightening Specifications .

Is there still exhaust noise?

--

--

System OK