Operation CHARM: Car repair manuals for everyone.

Noise Diagnosis - A/C System

COMPRESSOR
Resonant compressor noises are not a cause for alarm. However, irregular noises or rattles may indicate broken parts or excessive wear.
Excessive noise that comes from the inside of the compressor may be related to one of the following possibilities:
^ A defective piston shoe
^ A defective bearing
^ A defective cylinder
^ A defective shaft

In such cases, replace the compressor assembly. Excessive noise coming from the magnetic clutch face area may be related to a magnetic clutch or defective bearing. Replace the magnetic clutch if the noise comes from the clutch. If the noise does not come from the clutch, replace the compressor assembly.