I too im having this problem and know whats going on and how to fix the problem. The wast gates fail on the turbo/turbos. Mine whent out on the left, so when those do not open it causes presher that causes the oil leaks in the oil trap system. Volvo wants 900 for oil trap kit and 2200+ for new turbo. If you shop around online you can fined oil kots for about 350 amd a graded used turbo for about 150. So in parts itll cost you around 550+ then you need to rent a self service garage with lyft and air tools thatll b another 450+ because you need the space for a day and a half. So with all this said if you have the know how this repair will cost you around 1000 and some change and that beats the 4500+ to have these problems solved by the dealer or auto shop.
the is oil leak around the pcv housing .was also told during oil change and inspection by volvo dealership that is would be a future repair and possibly also will cause the cam seals to leak .it will cost $1,800.00 to have repair .I have not reapired this yet i am at 67,000 mile now and i am hearing the whistling noise and now have the cvvt solenoid failure .
have not fixed this yet ,i am ordering the parts today ! the dealership told me it would be a in the near future expense of 1,600.00 dollars in VA Beach, VA. I now have 61000. miles and have started to here the whistle :/ so time to fix .Hopefully cams seals are not leaking ,I am not loosing alot of oil since my oil change which at 56,000 is due again at 63000 miles where the oil was filled to top of the fill line on dipstick tube ,it has only leaked down to half way inbetween the botton and top fill line .planning on changing my oil,fule filter ,plugs ,plug wires and brakes now and starting to change the oil every 3000 to 5000 miles after this oil change and oil trap repair.I will be doing this repair my self then take to dealership to have computer updates checked,belt replaced and good look over car to make sure everything else including cam seals are good .I am a 35 year old femal .