Air/Wind Noise. Chevrolet Metro 1998

For 1990-2009 cars

Caution: An assistant should drive the vehicle while the technician checks for the location of the reported condition. Otherwise, personal injury could result.

Important: Often there is one primary leak source and one or more secondary leak sources that contribute to the noise condition. Repairing one of the contributing leak sources may not completely repair the total condition, but only reduce the condition.

1. In order to analyze a reported windnoise condition, test drive the vehicle. Many variables may singularly or collectively be attributed to creating the objectionable noise condition.
2. Use the following items during the test drive in order to aid in pinpointing and marking the areas of the leak:

• | A mechanic's stethoscope or a vacuum hose

• | Masking tape -- 51 mm (2 in) wide

• | Strip caulk

• | A screwdriver

3. Choose a regular route for the road test. The test road should include smooth and straight streets that run in the following directions:

• | North

• | South

• | East

• | West

4. Ensure that the area has little traffic or noise. These conditions will interfere with the test.
5. Drive the vehicle at the speed in which the noise was noticed by the customer or until you hear the noise.

Do not exceed safe, legal speeds.

6. Determine if the noise is an objectionable windnoise as opposed to the normal or the standard sounds.

The noise is external windnoise if the noise may be heard with the door window lowered while you drive the vehicle.

7. Locate an external windnoise condition by taping the following components until you eliminate the noise in order to pinpoint the exact cause of the noise:

• | The moldings

• | The gaps

8. If the noise cannot be heard with the windows lowered, one of the following conditions is present:

• | A body seam is leaking.

• | One of the following sealing surfaces is poor:

- | The window-to-weatherstrip

- | The door weatherstrip-to-door

9. Locate the source of the internal windnoise by taping off the body lock pillar pressure relief valves.

This procedure causes the following conditions:

• | The air pressure builds up inside the vehicle.

• | The windnoise is enhanced.

10. Internal windnoise is caused by air leaving the body.
11. Trace the suspected seal using one of the following components in order to locate the leak area:

• | A stethoscope

• | A section of the vacuum hose

12. Temporarily repair the condition using masking tape.
13. Adjust the tape as needed.
14. Continue testing in order to determine if one of the following conditions exists:

• | The noise has been eliminated.

• | Other leak areas exist.

15. After you locate all of the reported leak conditions, repair the condition using the proper alignment techniques and sealing materials as needed.