I have a 2014 Volvo XC60 D5 AWD SE Lux automatic with 20k on the clock. Over the past few weeks I can hear a whining noise behind the normal engine noise which is much more noticeable when the engine is under load. I gave it to a local Volvo service dealer. They said that they could find nothing wrong other than an air pipe which needed a new clip. I thought that it might be an air con issue, or worse still, a turbo issue. I would be grateful for your input.