Are you talking about the compressor noise or something else? The compressor noise is "normal", although you should be on the lookout for it happening too frequently when the car is parked. My car had a leak in the air system and would give a little compressor "burp" every minute or so in order to maintain pressure. Now that it is fixed it is very rare that the compressor runs. I work 10 feet from my car so I have a pretty good idea what it does all day.