Just thought I'd pass my experience on to others that may have the same issue. 2017 Raptor built at the end of June '17, delivered two weeks later in mid July. First oil change at dealer at 2k miles. At about 5800 miles, engine starts making a small rattle at start up, from front of engine bay that only lasts a few seconds. Becomes increasingly noticeable, especially when starting remotely as you could hear it from the outside and front more so than from interior. Note that the truck is stock and used mostly for commuting and hasn't been abused in any way. It's a third vehicle so is used about 700-800 miles a month, and has yet to be off road or haul a trailer. Took truck in for second oil change last month at 6,900 miles and asked them to check engine rattle. Ended up keeping truck nearly 4 weeks with lots of comm back and forth with Ford Performance/Engineering. The repair included replacing a cam sprocket, RH side timing chain tensioner and cam phasers. Engine is still quiet at start up now after 500 miles since picking it up. No complaints and love the truck - just thought I'd pass this along in the event anyone else is having increased front of engine start up noises that go away after a few seconds. There were no codes or any other abnormalities noted to my repair beyond the RH side chain tensioner was bleeding down after sitting.