Compressor Service

WARNING: This page does not describe the selected car, but rather 41 other vehicles, including the 2003 BMW M5, 2003 BMW M3, 2003 BMW 540i, 2003 BMW 530i, and 2003 BMW 525i. However, it is still accessible from the selected car via links, so may be relevant.

When troubleshooting a noisy compressor complaint, make sure the noise is present only when the clutch is engaged.
If it is present when the clutch is not engaged, remove the compressor drive belt and check again.
If the noise continues, it is not related to the compressor.
If removing the drive belt reduces or eliminates the noise, check the torque of the compressor and bracket mounting bolts.
Check the belt tension and condition, and tensioner pulleys which can produce rattling noises that would sound like a defective compressor.
A loose/slipping belt can cause noise.
A belt that is too tight can damage the clutch bearings.
If the compressor is noisy with the compressor clutch engaged, make sure the system is charged with the correct amount of refrigerant.
An over-charged system can cause compressor noise.
If the A/C system is overcharged with refrigerant, the liquid entering the compressor can damage it.
When troubleshooting a noisy compressor complaint, recover the refrigerant and recharge the system with the correct amount.
A failed compressor must be returned with the inlet and outlet ports sealed using the plastic caps from the replacement compressor. Otherwise the "failed" compressor will be damaged by moisture, and it will be impossible for Warranty to analyze it.