Inspection and Verification (Start Testing Here)

PURPOSE
Noise, vibration and harshness (NVH) are becoming more and more important because vehicles are becoming more sensitive to these vibrations. The purpose is to gain a working knowledge of the process of diagnosing NVH situations. The topics are discussed based on the description of the condition.

WHERE TO START
Become familiar with the terms. Use the Glossary of Terms to find the descriptive name of conditions not encountered before. After naming it, proceed to identify the condition and locate the proper diagnosis. Remember, by beginning at that point, most other systems in the vehicle have been eliminated; when the proper section is identified, the job is partly done. Follow the steps. Quick Checks are described within the step. Always follow each step exactly and make notes along the way to recall important findings later.

- If the condition occurs at high speed, the most likely place to start is under High Speed Shake in the Symptom Chart. Noise, Vibration and Harshness Diagnosis (High Speed Shake)

- The Road Test section describes how to sort the conditions into categories and how to distinguish a vibration from a shake. It provides hints on quick checks to make sure that a cause is either pinpointed or eliminated.