I have a 450c that loses power after about 30 minutes of use. Runs fine for a while then major loss in power. Almost seems like a lack of fuel issue. Like I am running out of diesel. I know what I don't think it is. I don't think it is a over heating problem as I have flushed the radiator and checked to make sure there is good fluid circulation. I also do not think it is a air filter problem as it was clean. What I think it might be is a injector problem or perhaps a turbo problem. Might be my imagination but I could have swore I use to hear it wind down when I shut the machine down now I do not hear it. But not sure. Also the pipe that goes between the turbo and the exhaust manifold is loose. I can turn it with my hand and leaks exhaust. Does the turbo need back pressure from that to work? What is throwing me off is that is runs fine for awhile then not so much. Any thoughts and ways to trouble shoot would be great. Don't want to fork over 700 hundred for a turbo I may not need.