I'm glad I joined here. This is a real issue. I have a 2016 Expy XLT and there is varying air leakage from all 4 windows. I've actually had people ask me if I had a window or door open.
After purchase, I took it to back to Ford, and they *********** all they could to make believe they couldn't hear anything. It caused me a bit of grief and has turned me off to future versions. This was my 3rd in a sequence of Bronco, Expy and Expy. I will give you what I found from my research. If the noise doesn't bother you, or you lease and don't care, that's fine. I paid big $ for my truck. It shouldn't do this. Technology from my last Expy (99) has gotten much better. It should not have this problem, and a lot of other owners don't have it.
Ford designers obviously took great care to minimize noise. Mine has a special sound-reducing windshield. The doors have double weatherstrip between the frame and the doors. I found all of the wind noise coming from where the glass meets the weatherstrip in the window channel. There is a really easy way to confirm it in yours. Just take a rag, sweater, whatever, and hold it up against the window channel while driving. In mine, the noise went away. Part of the issue is locating the source, because the sound reflects all over the place inside the truck.
I was able to find a thin, felt-like weatherstrip which I added to the window channel (self-stick on one side). This fixed the problem completely, but as time went on, the weatherstrip flattened and the problem came back. Using a thicker weatherstrip will not work because the power windows sense current rise, so if the window is pushing too hard on the weatherstrip before coming to the end of its travel, then the (BCM?) senses there is a resistance to closing and mistakenly thinks there is an object in the way. As a safety feature, it reverses the motor and lowers the window.
Based on everything I could find, I believe that the problem is that the window glass is not aligned properly from the factory and it will not seat into the weatherstrip evenly. That creates air gaps. Those little air gaps get worse as the weatherstrip ages. I believe that the corrective action (unfortunately) is to replace all the window channel weatherstrip with new, pull the door panel and align each window glass where it attaches to the regulator so there is a proper seating along the top and leading edge. Sadly, that is a bit of work that we as owners should not have to do. I will do it one of these days because I keep my vehicles on average for 10 or more years. I just haven't had the time to tackle it yet.
Try the rag test. See if your source is the same as mine, and please post your experience with this.
