2007 G6 Radiator Problem

Hello,

I have recently noticed that my 2007 G6 (82,200 Km) 3.5 V6 has been climbing up in temperature when driving. After parking the electric fan keeps running but if i start the car and sit with it a few seconds, the temperature goes down and the fan stays off. I have also noticed that there is no heat at all.

I do remember a time where I heard a gurgling noise coming from the passenger side dash, I assume this is the heater core. I am curious as to if I need to fill up the coolant, do a radiator flush, or if I have a air bubble in the system. I have heard that the bubbling noise could mean a blown head gasket, but I doubt that as the car runs fine other then getting hot.

Could the heater core be junk? It was fine a few weeks ago

Thanks

I would check the thermostat first... that could be stuck causing the overheating issue and lack of heat.