[TJ711]

Hello,
My moms 1996 Grand voyager 3.6 V6 (over 200,000 miles) has been having some problems with overheating. It all started when the radiator blew out the plastic part over 6 months ago. We towed it home and put a new radiator on, the A/C some how got messed up during the installation and hasn't worked since, but thats probably unrealated. It worked great after that untill a couple months ago, When the engine overheated in the parking lot, Somehow most of the water had leaked out, my mom was able to fill it with water and drive it home. We replaced the thermostat and put a new lid on the radiator, but it still loses water...very slowly... the way we've been driving the last 2 months is by refilling the plastic antifreeze reivoir with water every 40 miles, as long as the resivoir is kept filled the system won't lose water but when the resivoir goes empty the system loses water. It only loses water when the engine is on. after a drive the engine smells really hot but the heat gauge in the instrument cluster never goes past the middle(it could be broken). We've looked countless times for leaks both hot and cold and never seen a drip.
I'd aprecaite any help I can get.
Thanks in advance