I am having a whining sound that follows the engine as it goes thru gears. It sounds like a transmission whine. The weird part is that it only does it when the ac is on and I'm driving. It also only does it under moderate to heavy acceleration like going up a hill or getting on the interstate. If I am in park with the ac on and rev the engine I don't hear it. If I am accelerating and the noise is there I can switch off the ac and it will instantly go away.

Any ideas?
Thanks alot

 

It's the A/C compressor making the noise. Don't worry about it until it stops blowing cold.

 

My AC did that once and I shot some spray lithium luge behind the AC pulley and it went away. But it does sound like the bearings are getting dry or getting ready to go out.

 

Thanks guys. So even though it doesn't do it while in park with the ac on and reving the engine, you both still think its the compressor I'm hearing? Being under load maybe tightening the belt and revealing the wear in the bearings?

 

Putting it under a load will cause more drag.