A/C Compressor - Moan/Vibration, Idle or Off Idle
Number 87-1-1 Date 10/86Subject: A/C COMPRESSOR MOAN AND/OR VIBRATION, IDLE OR OFF IDLE
1984-87 GRAND PRIX SERIES
An A/C compressor moan or vibration at idle or off idle can be caused by a drive belt without proper tension. We continuously receive reports that technicians fail to achieve proper belt tension because they guess at the tension rather than use a belt tension gauge. The belt tension specifications are listed in Section 6B of the service manual, and it is essential that the belt tension gauge be used.
Another cause of moan or vibration that should not be overlooked is compressor mounting bracket bolts. Make sure that the bolts are all tight.