Engine camshaft and lifters failed and were inspected by Ford dealer, which corrected the issue by replacing the engine. Engine can failed and truck get stuck in the middle of the road. In the past 6 months its our 4th Ford truck with the same issue and a lot of other Fedex contractors that purchased a Ford truck with the 7.3L engine are reporting the same issue. No warning light was on in this vehicle, just started with a knocking sound that got worse until it got to the dealer and engine had to be replaced