Leaking Coolant and "idle Engine Overheating" wanrning
My wife was driving 2012 GMC Terrain through town and had the "Idle Engine overheating" warning flash up. She said there was no steam or anything. She pulled over, waited, and the vehicle started up without any issues. Earlier that day she mentioned a fan blowing after the engine was turned off. I arrived home and noticed coolant on the concrete, the reservoir empty. I examined what I could and assumed it was the upper hose that had defected. I flushed the radiator and was able to determine it wasn't an issue with any hoses, but seemed to be coming from the water pump despite not being able to get a clear look at it due to the compressed assemblies under the hood. How can I determine exactly what is wrong with this to fix it? Is it possible to tell if it is a bad water pump, head gasket, or thermostat?