I had an issue with my Jeep over heating after some heavy mudding awhile back which thanks to some helpful ppl on here it just turned out to be my mud covered radiator. After cleaning it out several days in a row it ran normal ever since. I normally don't use my a/c so I didn't notice until recently that when I run it the temp gauge rises to almost the third mark where normally in the past it's always been dead center and still is if my a/c is off. I'm also having to add water/coolant every week but there is no apparent leak. I took it to Chrysler and they did a high pressure test of the radiator and say they see nothing wrong and could not explain it, of course when they ran the air it did not rise. Seems not to happen if idle, only when moving, but if I turn off the air it does not matter how fast I am going it stays perfectly in the middle. I am unsure what to do at this point. Also even though the gauge is at the third mark, which seems pretty high, I never see any steam and have only smelled the vaguest scent of coolant, and still never see any signs of a leak. Any advice would be greatly appreciated, thanks!