A/C - Flutter or Moan Noise in A/C

File In Section: 1 - HVAC

Bulletin No.: 63-12-18

Date: January, 1997

Subject:
A/C System Flutter and/or Moan Noise with HVAC in A/C Mode
(Replace A/C Compressor Hose Assembly)

Models:
1996 Buick Park Avenue
1996-97 Buick LeSabre
1996 Oldsmobile Ninety Eight
1996-97 Oldsmobile Eighty Eight, LSS, Regency
1996-97 Pontiac Bonneville
with 3.8L Engine (VINs K, 1 - RPOs L36, L67)

Condition

Some owners may comment on a "fluttering" and/or "moan" noise during normal driving conditions with the HVAC system in the "A/C" mode. The noises become evident under light acceleration or deceleration with the A/C compressor clutch engaged. The noises are evident in the glove box area of the interior of the vehicle. The noises are most noticeable with the HVAC blower set on low speed with the engine operating between idle and 2500 RPM.

Cause

The "flutter" and/or "moan" noises are created by pressure pulses generated by the A/C compressor. The A/C compressor hose assembly transmits these pressure pulses into the body of the vehicle through the HVAC module.

Correction

This condition may be corrected by replacing the A/C compressor hose assembly with a new compressor hose assembly, P/N 25665518. The new compressor hose assembly contains an additional muffler located on the suction line (low pressure side of the A/C system). The additional muffler dampens the compressor pressure pulses. Refer to Section 1B of the appropriate Service Manual for replacement procedure.

Parts Information

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation Description Labor Time
Hoses and/or Lines
Refrigerant - Replace Use published
D3088 (Compressor Suction labor operation
& Discharge Hose time
Assembly)
Add Recover/Recharge 0.7 hr
A/C System