Okay, I have a few questions. This past weekend, I drove my Jimmy further than it's ever been in the time that I've owned it...which isn't all that far, just the other car broke down. I noticed that it started smelling hot. The temp guage never hit 200, but I know they aren't very accurate. I let it cool off, I pull the radiator cap off, and topped it off (it wasn't very low) then I started it up. I also filled the overflow about halfway. I let it run about 10 minutes but the level never went down. It did start to come out the top of the radiator however. Does this mean my thermostat isn't opening? I plan to replace it this weekend with a Robertshaw 180 Degree(per the dieselpage) if I can find one (PM me if you know where to get one). I also think my overflow is leaking as it's not half full anymore...and it was dripping under the truck. I also noticed that whenever I had a passenger, my truck had a very loud low frequency vibration...WTF is that about? I don't know if it coincided with the hot smell, because after I soaked down the radiator, it stopped, but the passenger got out of the truck about the same time...so I'm confused. Any help I can get would be greatly appreciated. Thanks as always. While I'm at it...I would like to discuss some cooling options for the 6.2. I know there have been experiements in this group as well as the Diesel page about different types of fans and radiators...what would be best for my daily driver/soon to be wheeler? I want to have this thing last forever. I plan to install a Tranny/power steering cooler in the future, but right now I want to plot out my engine buildup. Anybody who wants to brainstorm with me, let me know, I could talk about this stuff all day.