losing water

A pressure test of the cooling system should be performed to find out where the coolant is going. It's unlikely to be an "internal engine coolant leak" due to the engine being all aluminum, and unlikely to "warp" causing a cylinder head leak. You will find a coolant leak once pressure is put to the system. Also, if there is no leak, there could be an air pocket in the cooling system that has been there following radiator replacement -- purge all air out of the system professionally before moving forward. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops