Operation CHARM: Car repair manuals for everyone.

Noise Diagnosis - A/C System

BLOWER NOISE
A constant air rush noise is typical of high speed blower operation. Some systems and modes are more noisy than other systems. It possible, verify the noise using a similar vehicle in order to determine if the noise is typical or excessive.

VIBRATION/RATTLE

IMPORTANT: Feel the lines, the hoses, and the brackets during the diagnosis. Many noises stop when you contact the component.

Potential causes include the following conditions:
- The belt is not in proper alignment in the pulley groove.
- The belt tensioner is faulty.
- The lines or the hoses are in contact with each other.
- The brackets are loose.
- Other drive components are faulty.

MOANS
Potential causes include the following conditions:
- The A/C charge is not proper.
- Other drive components are faulty.
- A bracket is loose or is not in proper alignment.
- The lines or the hoses are in contact with each other.
- The heater hoses are not correctly routed.

SCREECH
Potential causes include the following conditions:
- The belt is serpentine.
- The compressor bearings are faulty.
- The compressor clutch is faulty.