7300 exhaust blowing out intake

[dhabicht1]

Does anyone know what this may be a symptom of?

Thanks,

Doug

 

[Fordlords]

The 7300 has a Mitsubishi turbodiesel correct? If so, I would first check for a restricted muffler, possibly filled up with carbon. I had this same problem brought to me in A JD/Yanmar CUT and that is what it turned out to be- the muffler was so filled up with carbon that the exhaust could not get out of the manifold, turbo and cylinders and was coming back out the air intake. Pull the muffler off and run it without it on for a few minutes and see if that solves it.

-Fordlords-