I have a 2010 XC90 with about 88K miles. For the last several years, we've had a whirring noise that only occurs when the AC is turned on and the engine has been under load. The noise changes pitch as the engine accelerates and decelerates. I've taken it to several dealerships in the States, but none could replicate the noise.
Finally, in Germany, the shop heard the noise, but they had never experienced any problems like this one. The service manager said that he had never seen anything like it. He said he could swap out the fan electronic module, but that would be about 700Euro and may not fix the problem.
Has anyone had this type of problem? What did you do about it?

 

That's different...

I would assume it has something to do with the AC compressor especially since it's related to engine RPMs. I'm not sure what changing the fan electronic module would do...seems like nothing.

AC clutch maybe? I'm no expert so I could be way off but hopefully this gets the conversation going here. Good luck!