Lock whirring sound
 

Just acquired a 2004 XC70. Drove it 14 hours to bring it home. Great vehicle!

Only one issue which I knew about when I got it. The front passenger power door lock does not lock or unlock except if pushed in or pulled out manually. When locking/unlocking with the FOB or switch it makes a whirring sound. Have not opened up the door panel yet. Could it be that something got disconnected or came loose inside that its trying to engage but not engaing?

It looks like its a fairly common issue but have not foumd a good answer yet. I would appreciate any information.