About 2 years ago the aircon developed a whirring whining noise which goes up and down with engine revs., It goes off when we switch the aircon off. Noise comes on after 5 mins or so and gets louder until we turn off the aircon as it gets on your nerves. Noise seems worse on the engine overrun. We had the car into the Vauxhall Dealer and it was no better but they did not charge. I took car to an aircon specialist who repressurised the nsystem (nothing wrong with that) a couple of times since abd he came out with me in the car. Unfortunately he lives in a busy area in Birmmingham and it was difficult to hear the noise so soon after we went out. As soon as he left and I drove home it started up again. As with most car noises like bearings it's best to leave it until it gets really bad then people can diagnose it. This noise has not got muuch worse, and is never too bad when I take the car to get it fixed. Has anyone else experienced this and can telll me what this noise is due to? - Noisy