1 /5 Zeb Howard: Had my truck in there a few weeks ago and was told we needed a new engine to the tune of 13-15k, said we had a bad wrist pin or the piston was slapping the cylinder wall. Picked the truck up and decided to do some more homework for myself. Found 6.0 injectors can be a little picky when it comes to oil so I decided to change the oil and use motorcraft 15/40 with arcoil additive (had delo 15/40 synblend) and low and behold within a week of daily driving the engine noise disappeared. Wouldnt even have left this review except I was assured by the guy who diagnosed the truck that the engine was toast, and yet it was not. When I asked how he diagnosed it, the only method he cited was his many years of experience and how many times hed seen this issue. I know people mess up but an oil change fixing a bad engine.....Thats kinda over the top.