I HAD a 2013 F-150 5.0 with 125K miles, until it started developing a rough idle. Tried to check and fix everything I could until I reached my limit. Took it to the dealership and was told that I needed a new engine to the tune of almost $12K. Took it to a couple of independants who said that while I might not need a new engine, I'd at least need a head job on both sides which was still going to be a rather costly proposition.
What weighed heavy in the decision process was that the service director said they had another 5.0 in the shop with the exact same problem. Some research on the internet leads me to believe there are some inherit design problems with this engine, especially that back cylinders. I didn't want to dump a bunch of money into the truck only to have problems popping up in the not to distant future. Also, 12K off on a remaining Ram 4x4 crew cab diesel helped to seal the deal.
I hope all that have the 5.0 have better luck than I did. I had planned on keeping the truck for several more years and passing that truck down to my son in a few years, but I guess plans have changed.
