A/C Compressor - Growling Noise
NO.: 24-27-93GROUP: Heater & A/C
DATE: Nov. 19, 1993
SUBJECT:
A/C Compressor Noise
MODELS:
1991 - 1993 (AD) Ram Pickup/Ramcharger
1991 - 1994 (AN) Dakota
1994 (BR) Ram pickup
1991 - 1992 (MJ) Comanche
1991 - 1994 (XJ) Cherokee
1991 - 1994 (YJ) Wrangler
SYMPTOM/CONDITION:
A growling noise may be heard with the A/C compressor running.
DIAGNOSIS:
Run the vehicle in neutral with the A/C system operating in the normal A/C mode with the compressor engaged and the blower fan operating at low speed. Raise the engine RPM slowly until 2500 RPM is reached while listening for the noise. If the noise is heard, disengage the compressor by turning the A/C system to the heat mode or by depressing the A/C button. If the noise goes away when the compressor disengages, perform the repair procedure.
PARTS REQUIRED:
NOTE:
THIS BULLETIN APPLIES TO VEHICLES THAT USE EITHER R12 OR R134A. REFER TO THE SERVICE MANUAL FOR THE MODEL BEING REPAIRED AND USE THE APPROPRIATE SERVICE PROCEDURES AND RECOVERY EQUIPMENT FOR THE SYSTEM THE VEHICLE IS EQUIPPED WITH.
REPAIR PROCEDURE:
This bulletin involves installing a revised A/C compressor valve plate assembly.
NOTE:
IN ORDER TO MINIMIZE THE ABSORPTION OF MOISTURE INTO THE A/C SYSTEM, DO NOT LEAVE THE SYSTEM OPEN TO THE ATMOSPHERE ANY LONGER THAN IT TAKES TO PERFORM THIS PROCEDURE.
1. Using the procedures outlined in the appropriate service manual, discharge and recover the refrigerant using approved refrigerant recovery equipment.
2. Remove the compressor. Mark the compressor body and cylinder head to aid in alignment when assembled.
3. Remove the six cylinder head bolts from the compressor and remove and discard the valve plate and original gaskets.
4. Align the new gaskets with the pins on the valve plate and assemble the valve plate and cylinder head to the block using the marks made earlier.
5. Install the six cylinder head bolts and snug them to the block. Tighten the cylinder head bolts using a cross or star pattern to 22-25 Ft.Lbs. (34 N-m).
6. Install the compressor and related hardware using the new seals listed above.
7. Evacuate the system for at least 15 minutes (providing that the system was not left open to the atmosphere for any extended period of time). Fill the system with the appropriate refrigerant charge.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE: (Except Diesel)
Labor Operation No. 24-10-01-94 AD, AN, BR 1.3 Hrs.
MJ, XJ, YJ 1.0 Hrs.
(Diesel Engine)
24-10-01-95 AD, BR 2.0 Hrs.
FAILURE CODE: 68 - Noisy