i was driving my truck pulling my atv and the check engine light came on. and then the truck started to clattering really loud. i pulled over and shut the truck off then started it and it was fine i drove about 20 miles more and it did it again. but this time it would not come out of it. it sounds like a brokin piston or a vavle has let loose. but i dont know much about diesels. when it comes to gas is where i have spent my life under the hood making power.