GM Service Manual Online
For 1990-2009 cars only

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 secondary leak source or more 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. One variable or many variables may cause the incorrect noise condition.
  2. During the test drive, use the following items in order to aid in finding the leak and in marking the areas of the leak:
  3. • A mechanic's stethoscope or a vacuum hose
    • Masking tape -- 51 mm (2 in) wide
    • Strip caulk
    • A screwdriver
  4. Select a regular route for the road test. The test road should include smooth roads and straight roads that run in the following directions:
  5. • North
    • South
    • East
    • West
  6. Verify that the area has little traffic or noise. These conditions will interfere with the test.
  7. Drive the vehicle at the speed in which the noise was noticed by the customer, or until you hear the noise.
  8. Do not exceed safe, legal speeds.

  9. Determine if the noise is an incorrect windnoise, or an acceptable sound that is normal or standard.
  10. The noise is external windnoise if the noise may be heard with the door window lowered while you drive the vehicle.


    Object Number: 239310  Size: SH

    Notice: If masking the grille or headlamp bezel areas, care must be taken not to restrict airflow. Restricting airflow can cause vehicle overheating.

  11. Locate an external windnoise condition by taping the following components until you eliminate the noise in order to locate the exact cause of the noise:
  12. • The moldings
    • The gaps
  13. If the noise cannot be heard with the windows lowered, one of the following conditions is present:
  14. • A body seam is leaking.
    • One of the following sealing surfaces is poor:
       - The window to the weather strip
       - The door weather strip to the door
  15. Locate the source of the internal windnoise by taping off the pressure relief valves of the body lock pillar .
  16. This procedure causes the following conditions:

    • The air pressure increases inside the vehicle.
    • The windnoise is enhanced.
  17. Internal windnoise is caused by air that is leaving the body.
  18. Trace the suspected seal using one of the following components in order to locate the leak area:
  19. • A stethoscope
    • A section of the vacuum hose
  20. Temporarily repair the condition using masking tape.
  21. Adjust the tape if necessary.
  22. Continue testing in order to determine if one of the following conditions exists:
  23. • The noise has been eliminated.
    • Other leak areas exist.
  24. After you locate all of the reported leak conditions, repair the condition using the correct alignment techniques and the correct sealing materials if necessary.