For 1990-2009 cars

During the last 10-15 years, vehicle design and engineering have dramatically changed due to the following factors:

• | Increased fuel costs

• | Decreased fuel supplies

• | Corporate Average Fuel Economy requirements

• | Clean air legislation

• | Foreign competition

• | Ability to withstand collision

• | Rising customer expectations

Vehicle designs have evolved from full-frame construction to lighter unibody designs. These designs transfer noise and vibration much more readily.

The manufacturer has greatly reduced the use of heavier and smoother running V8 engines, replacing these engines with lighter, more fuel-efficient 4-cylinder and 6-cylinder engines. During this same period, options such as the following have become increasingly popular:

• | Air conditioning

• | Power steering

Such options increase engine load and can also generate unwanted noise and vibration.

Customer perception of quality can be directly linked to the presence or absence of unwanted noise and vibration. A technician's ability to quickly diagnose and repair a noise or vibration directly affects that customer's loyalty to the dealership. Technicians who are capable of satisfying this need will be highly regarded and in great demand.

The intent of this section of the service manual is to provide a systematic approach to vehicle vibration diagnosis and correction. By using Strategy Based Diagnosis and troubleshooting philosophies covered in this section, technicians will be able to provide effective and timely repairs.