2003 Dodge Intrepid coolant loss

If you can't see any external leak, it may be burning through your engines exhaust. A cylinder head, or gasket can leak, and coolant mixes into the combustion chambers. Ok You can test it in several ways, a pressure test can locate it or an engine combustion leak tester will pick up combustion chemicals in your cooling system, also.

Yes, but not very often at the rate your adding, especially if your parking in the same area. If it was filled to the top, when the engine was cold it will overflow. A overflow bottle is normally used for filling the system, and should be filled to the full hot line, only after the engine is good and hot. Only remove the radiator cap when the engine is cold. On a 6 cylinder the possibility exists that the engine is losing it down the side of the block, and burning off also. The heater core inside the car does leak also. You'll smell coolant inside and a wet passenger side carpet. If your thinking this is the cause, after you park it put a piece of cardboard under the bottles area on the ground. Since the antifreeze is a type of oil, it does not evaporate so fast. If you have it serviced, and it is internal in the engine, evaluate the cost of repair against the overall condition of the rest of the car. I do hope it is only the overflow bottle. But the bottle overflowing is also a sign of air or combustion entering into the cooling system. I would have it pressure tested, it should not cost much, nor does a kit that checks for a head or head gasket problem. Ok Welcome.