Rob in CA
Full Access Member
My 2014 does the exact same thing. Sounds like a turbo spooling up. I can reproduce the whistle only under a driving load at 1500-2000 RPMs. I had a Ford tech from my dealership ride with me and was able to reproduce the noise over and over for him. He popped the hood and checked the air intake. He said the noise was not affecting the performance of the truck and didn't know what was causing the noise. The truck is completely stock with 18,000 miles.
That's exactly what happened to me. The tech drove with me, and heard the noise. Dealership called me back a few hours later and said the truck was fine. I haven't noticed any performance degradation, but the sound is getting progressively louder, so to me that is not normal.