I've never had the pleasure of owning one and in fact I don't know much about them but I heard an absolutely stunning tale the other day. The truck is 2015 extended cab model full size box, driven rather mildly by my wife's uncle. During his commute, it suddenly stutters, shudders and loses power, entering limp mode. After arriving at work he calls the dealer who picks it up on a flat deck and takes it back for diagnosis. They diagnose a stretched timing chain and scored cam caps. The prognosis is fatal - it requires a new engine, but it's under warranty.
2 weeks later, the new engine is installed and they call to say it's just about ready for the test drive and they'll call when it's back. 15 minutes, 30 minutes, an hour goes by. 2 hours later they call to report that unfortunately there was a problem - it made "bad noises" when started and then they pieces of bearing in the oil pan. It was going to need a new engine, but there was a problem. Ford no longer manufactures this particular engine and hasn't for a while. All of the warranty engines are remanufactured by a 3rd party on Ford's behalf but there seems to be a large number of warranty issues leading to a supply problem. They weren't sure how long it was going to take to get another engine.
The reman engine arrives at some point and is installed. This one makes it to the test drive but has a valve stick, smack the piston and make a mess out of everything.
3rd replacement engine in a single repair. 2 + months in and he's only just got the truck back but so far so good.
I've since read a little bit about charge air coolers causing condensation-related water damage (which doesn't seem germane here), some typical posts outlining horrendous problems, and a handful of posts defending it as a solid and reliable engine. It certainly strikes me as something to avoid in the used truck market.
