Same here. I noticed because the IC cracked at the bottom and it started to leak oil. Some days it looked more like condensation and others just oil. I'm pretty sure it's from the PCV. I really quizzed the dealer on the issue when I had the IC replaced but they couldn't tell me where it was coming from. I need to install a catch can one of these days.
2012 F150 EcoScrew 4x4 XLT 157"wb MaxTow