Q: Keep having to add coolant

Hello. You really should not have to add coolant to this engine. If the system is sealed and working as designed then there should not be any issues. Most of the time, this occurs because the water pump leaks. I have seen a lot of water pump leaks on this engine and they typically are slow enough to where they do not drop any coolant on the ground. I usually do a pressure test on the cooling system to find the leak. If the engine has overheated in the past, then it may have an internal engine problem but that is not as common. If you want to have this coolant loss issue inspected, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.