Ok so I know there are lots of threads on valve cleaning, how to keep them clean, that Ford doesn't have an approved cleaning method blah blah blah. My question is about Ford though, so they don't have an approved method for cleaning, what to they do to fix carbon build up, do they recognize it as an issue? Do they just replace the heads? I'm just curious cause I have a 2018 and got the extended 100k warranty and was wondering what they do when carbon build up starts to cause issues? I've been looking locally for a reputable shop in or around York PA that does it, and so far I have only found 1 shop about 2 hours away, I have read online BMW has a media blasting method for valve cleaning at their service shops and don't know if they have that at every shop or just certain ones, and if they do have it at one of their shops near me if they would do a Ford ST?