I have a 98 jeep cherokee with the 4.0L motor. For some reason I keep losing coolant from the reservoir while the level in the radiator pretty much stays the same. If I fill the reservoir to the full mark it takes about two days for it to empty. I thought there was a leak in the reservoir itself so I replaced it, but that didn't fix the problem. I've done other work to eliminate leaks in the radiator, and coolant system (i.e. replacing hoses, clamps, radiator cap, etc.), but I'm pretty sure I see coolant in the engine compartment where the reservoir is, and I haven't noticed any around the radiator. Any ideas?

 

are you over heating?

 

I overheated once over the winter, and it was running hot a few days ago in severe heat, other than that it's been just below the 210 mark.

 

have cooling system pressure checked also do rad cap test,check for coolant in oil

 

^ that or you probably have introduced some air in the head. Try bleeding the coolant system from the upper heater hose with the Jeep facing up hill; especially since you replaced those components.