Hey guys, My G5200 HST Diesel is running hot lately, I can get about 45 minutes out of it before I have to let her cool down and top off the radiator. I first noticed it a couple weeks ago, and now am babying it every 30-45 minutes, so I dont let it overheat or run out of coolant. I keep the oil, filters & fluids checked and changed on a regular basis, but not understanding whats going on. Could this be a thermostat issue? What do you guys think?