Initial Inspection and Diagnostic Overview: Overview

The information will provide a working knowledge of the process required to diagnose a noise, vibration, or harshness (NVH) situation. Before attempting to diagnose an NVH condition, read the diagnostic theory and glossary of terms.

After becoming familiar with the methods and terms used in NVH diagnosis, proceed to the diagnostic procedures. The most important part of diagnosis is the road test. The wide range of NVH is defined and narrowed to a specific area of the vehicle.

With the type of condition known, the diagnosis and testing procedures are used to define the diagnosis of a specific component. After making any repair, always road test the vehicle to confirm that the condition has been corrected to the owner's satisfaction.

Before entering the diagnostic chart, study the diagnostic theory and glossary of terms. The information here will help form an approach to NVH diagnosis and will also define the terms commonly used in NVH diagnosis. NVH usually occur in four areas:
- Tires.
- Engine accessories.
- Suspension.
- Driveline.

It is important that an NVH problem be isolated into its specific area as soon as possible. The easiest and quickest way to do this is to perform road test.