I came across this video showing a remedy for fixing "cold start rattle." Although the engine is a 2011 F150 3.5L Ecoboost, in my opinion, it has a blown hydraulic tensioner or bad OEM phasers but check out this so called solution. I about fell off my chair...

 

Not the worst thing I have seen someone do lol

Seems to be a temp fix for his issue

 

It probably would have been less time consuming and cheaper to fix the problem not to mention now having to remember a startup sequence. I hope he doesn't lend his truck to anyone.

 

Yeah and this is a reminder that you never know what people do to a truck before you by it