I noticed back in August that the overflow tank in my Jeep XJ was at the half way point between safe and add for coolant... well just changed the oil, and I noticed it's at the add mark. I had topped it off one other time before this.. normal? No leaks anywhere, and engine doesn't over heat?

78K miles on the engine.. all original not rebuilt.

 

What year? Are you adding actual coolant or water? May be a little evaporation. How long did you go between adding? If you've only added a quart or so since August I wouldn't consider that a problem and myself would probably settle on "probably evaporated," but I don't have an 0331 to worry about.

Closed coolant here, really easy to figure out how you're losing coolant on those...

 

1995. The last time I noticed it needed to be topped off was back in August.. so in four months it went from the full to the add mark on the overflow.

The previous owner had the radiator replaced a couple years back (I wanna say 2005/2006ish). The coolant itself inside the radiator looks fine when I remove the cap


Edit: Topped off with pre-mix 50/50

 

I'm gonna settle on "it evaporated" as my final answer and will let someone else with more knowledge take it from here.

 

See how long you go before you need add it again and how much.

 

My 99 goes through a full bottle in 2 months from the heater core leaking then evaporating.