Q: The problem I'm having is overheating and then water starts to come out of the overfill hose on the reservoir.

Hi there. If you have removed the thermostat and the engine still overheats, then there could be an issue with the water pump or the head gasket. With the engine running at operating temperature before it gets hot, check the upper and lower hose and see if there is any temperature change. The upper hose would be warmer than the lower hose. If he hoses are about the same temperature, then the water pump is working. If the hoses are different temperatures, then the water pump may not be working. Also, get a block tester kit from a local parts store and use it to check the steam coming out of the reservoir with the cap removed. Be very careful as coolant can burn skin when it is very hot. If the blue chemical turns from blue to yellow or green, then there is carbon in your coolant, which would mean that the head gasket is burned. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your overheating issue.