Changed the thermostat because it was over heating. Old thermostat was stuck in the open position. Replaced with a new one and it is still over heating. Does the system need to be burped? I did put a gallon of water in it to get me home. Could that also be an issue?

 

was a failed thermostat the reason it was overheating? Or where you throwing parts at a problem with no diagnosis? Generally the only way a t-stat will cause a vehicle to overheat is if it fails closed.

I would say you problem lies elsewhere. There multiple components in cooling system that can fail. It may be time to rebuild the cooling system.

 

You will have the best response if you post in the Jeep "Grand Cherokee" forum. This one is for regular "Cherokee" XJ models. These forums are platform specific.

Post HERE:

https://www.cherokeeforum.com/f5/

If your 2000 Grand has original cooling equipment, I completely agree with Curry in that you should consider rebuilding the cooling system. The parts themselves are not that expensive if you can do the work yourself. Radiator, radiator cap, fan clutch, water pump and don't forget hoses as they can rot from the inside out. The money you spend on cooling system maintenance is likely the best money you can spend on your vehicle. Overheats are very hard on the engine and they can result in things like a blown head gasket, cracked head. It's "pay me now or pay me a LOT more later". Don't drive this vehicle until it is resolved and verified.

Good luck!