NVH Diagnostic Procedure Notes (Read First)

HOW TO USE THIS DIAGNOSTIC PROCEDURE
Noise, vibration and harshness (NVH) diagnosis is becoming more and more important as vehicles are becoming more sensitive to these vibrations. This section is designed to give a working knowledge of the process of diagnosing noise and vibration situations. It is divided into several sections with each section based on the description of a condition. If a condition occurs at high speed for example, the most likely place to start is under High Speed Shake. The Road Test portion will tell how to sort out the conditions into categories and how to tell a vibration from a shake. It will also give a few hints on quick checks to either pinpoint or eliminate the cause.

Become familiar with the terms. After verifying the concern, proceed to the section entitled Identifying the Condition and locate the proper diagnosis section. Remember, just 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 within the section. Quick Checks are described within the step, while more involved tests, inspections and adjustments are found in Adjustments. Always follow each step exactly, and make notes along the way to recall important findings later.