Yesterday while moving dirt with the carry all scraper under full power and pulling hard it sounded like the turbo was screaming and ready to come apart.  As soon as you quit pulling the engine hard the noise would go away. No smoke or lack of power so Im guessing its not the turbo but something elce… After looking close I see I have two exhaust bolts that are missing. It shows no sign of leaking out throu the manifold to the outside.   Could this be the nosie that I am hearing when its under full load?