My coolant hasn't been filled in over 6000 miles, however the temp gauge went a little higher than usual recently. The tank was less than half full. I have not had a chance to have it in one place long enough to see if it is leaking externally. Where do I need to start looking to fix the issue?

 

the radiator cap

 

look up and down the engine for watery liquid. look below and run your glove under there if you see any fluid. smell the fluid, coolant should be easy to smell . it smells and looks different from oil. obviously look up and down the radiator itself seeing as how that's where coolant goes in. and there are the huge upper and lower radiator hoses, look and inspect them. feel underneath those large hoses for coolant at the ends of the hoses at the connections