Has anyone experienced a boost leak on their Td6? We have a 2017 with about 112k on it. Recently started making a loud whistle noise but only under load when accelerating hard either to pass or merge onto highway at 55mph +. Can't get the noise to happen when parked or driving around at lower speeds revving.

 

Had one recently. Split hose which opens up under boost, so no noise when driving gently on level or when idling.
If it becomes too bad it will throw up a P0299 code and put you into restricted performance.
Check around the hoses from intercooler to inlet manifold for oil mist buildup which will be a dead giveaway for the leak's location.

 

Apparently mine had a leak from a loose egr connection after my Passenger side EGR was replaced.