I have a 2005 caravan overheating. I replaced thermostat, radiator, water pump, and Dorman hose. Sometimes it will run a day or 2 no issue. Then back to overheating after filling with antifreeze/water. We ran both front and back heaters on high to avoid any air pockets. Sometimes I see water on ground under over flow. Other times I don't. I see bubbling fluid next to valve cover right next to thermostat and thats dry. The oil is normal not milky. But sometimes I go through a gallon of fluid in a 10 minute ride. But like I said sometimes it has no issue. I'm really at a loss. Great running van when its not over heating.

 

This sounds like a leaking head gasket, but if you saw bubbling near the valve cover, that indicates the lower intake gasket is leaking. Either one would account for coolant loss.

Rent a pressure tester from a parts store. Pressurize the system to the rating on the cap and look for leaks. Perform the pressure test with the engine cold and hot, and don’t forget to test the pressure cap itself as well. If there’s no signs of external leaks, pull the spark plugs to check for coolant leaking into the cylinders.

The transmission cooler may also share the radiator, so check condition/color of the ATF as well.

 

If the pressure test is inconclusive you can also test for combustion gasses in your coolant. The pressure in the cylinders during combustion pushes out exhaust fumes into the coolant and can be tested for using a reactive liquid.