Okay so I am a newbie here I have done some work myself but I have not been able to figure out what this annoying whining noise is when I turn on the A/C and the car is in gear? I have made a video with the A/C off and with the A/C on and in gear and you will hear it kick in about the last 35 seconds of the video when I turn on the A/C and place the vehicle in gear. I have my suspicions that its an idler pully going bad but I do not want to spend money guessing. I have new belts to put on and I have already replaced the dreaded PCV valve, and the oil filter housing gasket is next on the list of repairs to be performed. I put new plugs in last weekend also.
Vehicle specs: 2003 E53 3.0i automatic 153,000 miles
2003 BMW X5 Engine Noise - YouTube