Shrill whistling type of noise-anybody have any idea what it could be? on 1998 Mercedes-Benz SLK230

This shrill noise is intermitent and seems to stop when I speed up, yet it gets louder as I slow down and stops when the car stops. I don't think it's the AC since I turned off the AC and the noise didn't stop.
If anyone else has experienced this any information that could be passed on to me would be greatly appreciated.
Thanks, CR

2 answers 2 comments
I would start by checking the the condition and tension of your belts. Also look for any coolant that may be leaking on to the belts. Then I would check all the pulleys that the belts turn, there may be a bearing that is wearing out. It does not sounds like a wheel/axle type noise because that would generally intensify with speed.
I had to bring my car to the shop this morning, it was really making a strange noise. I saw one of the belts wasn't in the correctly positioned. You are right on with your answer...need a new water pump and belts. Thanks and have a great day.
Unfortunately noises are a very subjective condition that would require us to hear to be able to determine the source. Please feel free to call us at 954-713-1000 and schedule an appointment. We could go for a test drive with you to hear the noise. Thank You
Thank you for your reply. Problem has been identified and solved.