09 Prostar running hot

[Rawze]

Sounds like you did most of the normal stuff. If I owned it, I would be taking things apart again and verifying there was no issues with the cooling components, Thermostat, radiator, CAC, A/C condenser, and sensor(s), cooling fan, etc. I would ensure there were no blockages in the cooling passages in the engine and other components too. I would ensure air was not getting into the system and causing flow problems. After that, I would be pulling the emissions system cans off and having them cleaned, baked, and flow tested. I would verify the programming was correct, and that the the static timing of the engine was correct too. I would be pulling the pan off and inspecting the rod and main bearings as well, looking for anything that might be causing too much internal friction. - It is not rocket science,.. it is an engine.

You never did mention what boost gets up to or your pyro temps. ANYONE who does not have those gauges are only driving it blind in my opinion anyways. Without them, a person has no clue or guide-point towards driving a truck efficiently. Even those who claim to be really good drivers do much better with those gauges if they drive by them after they are installed. - Just my own take on it anyways.

For all you know, without boost or pyro gauges, the turbo could be making 50 lbs of boost pressure and over-boosting like mad, putting the engine into a serious internal strain. I know of one guy who cracked 2 heads before he finally put those gauges on,.. and the day he did, he found out his turbo was way-over-spooling due to a bad exhaust gas pressure sensor that never threw any kind of fault.