This noise has been going on for about 6 months now just ignored it because never had the cash to fix it but now i do. Its a loud metalic ping sound happens randomly when im driving and a couple times when its sitting in idle or shut off. It happens everyday. Nothing wrong performance wise with truck everything is normal and drives good just its getting annoying. someone posted same issue awhile ago saying it was the motor cooling down faster than turbo and manifold or somthing like that. just want to know if this is a major issue that needs to be fixed asap? bringing in to buddys shop tommarow anyways to get looked at. let me know what you think, thanks.