I have a 2007 V70 2.5T with 70k miles. Recently I am having a high pitched whine from the time I start the car to when I turn it off. I have removed the oil cap with it running to determine if it is the breather box. No change in the whine. It comes from the driver side of the engine below the battery and air filter. It looks to be a silver circular component, does anyone have any idea what it is? What is causing the whine? is this a serious issue? I have not had any CEL come on.It is driving me nuts.

Thanks

 

Are you talking about the turbo ??

 

How to Diagnose Turbo Chargers | eHow

 

Where are you at with it ??