I have a pre owned 2016 C-Max Energi with 13k miles and noticed this noise behind dash. I have another 16 and know that is is not normal. First dealer said it was normal. I know it is not and trying to get an idea what this could be.
Link is to vid of sound.
Oh yeah that's normal. Just kidding. Pains me that dealers call some noises 'normal'. If it's normal, then all of that make would do it and it wouldn't suddenly show up. Normal? Well, dealer, then let's drive all of those on your lot so we can verify that.
I'd recommend escalating this to the service manager and general manager and then try another dealer if that doesn't help. Trying FORD might help, but they'll initially tell you to try working it through your dealer. FORD is often of little help b/c they have little to no authority over the dealers.
Good luck and please let us know how it goes!