Ok Im new this is my first ty I bought it from the orig owner the truck has almost 300k on it and everytime the thing farted it was in the shop. it has had nothing but mobile one oil, and was owned by a senior.(not drove hard) this guy even kept record of everytime he got gas. the problem im having is once its warm and you sit at a light or get into light boost 5psi or so it has light smoke. however it doesnt do it all the time,motor has great compression and you can rev it in park and it wont smoke most the time. truck has a rebuilt oem turbo with 45k on it. I was told valve guides or the turbo. its just really wierd full boost no smoke and it only smokes on light boost about half the time. any help thanks