For 1990-2009 cars

# Knocking Sound From A/C Compressor (Replace Compressor)

Subject: | Knocking Sound From A/C Compressor (Replace Compressor)

Models: | 1997-2001 Cadillac Catera

### Condition

Some customers may comment on a knocking sound from the A/C (air conditioning) compressor.

### Cause

This condition may be caused by an internal tolerance stack-up in the compressor.

### Correction

Perform the following A/C system checks and correct any concerns that may be found. Only after these checks have been done and any concerns found are corrected, should the A/C compressor be replaced.

1. Verify the customer concern if possible. Please note that some compressor noise is considered normal. It will vary with the different operating conditions of the A/C system and the vehicle.
2. Refer to Corporate Bulletin Number 01-01-38-013. Use the information contained in the bulletin to diagnose any concerns that may cause the A/C compressor to be noisy. Correct any concerns that are found.
3. Perform the Air Conditioning System Performance Test found in SI. Correct any concerns that are found. The A/C system charge weight and TXV (Thermostatic Expansion Valve) operation are critical to check in this step.
4. If the A/C compressor is still noisy after any concerns found in the previous steps have been corrected, only then should it be replaced. Refer to the Compressor Replacement procedure in SI for instructions. The A/C compressor part number listed below is for an updated design part.

### Parts Information

Part Number | Description | Qty
--- | --- | ---
24432574 | Compressor, A/C | 1

Parts are currently available from GMSPO.

### Warranty Information

For vehicles repaired under warranty, use:

Labor Operation | Description | Labor Time
--- | --- | ---
D4440 | Compressor Assembly - Replace | Use published labor operation time.
Add: | Diagnosis Time | 0.0 - 0.3 hr