I have a 07 gt that has done this off and on since July of 2012. List of things replaced are in this order; fans, relays, and thermostat. Issue continued but dealer could not duplicate 2 times that I brought it in, so I drove it til it got hot enough to spew out in their drive. After that replaced wire harness and fuse or control panel in September. Problem was fine til last week so brought back to dealership and they say the wire harness melted again the panel has melted and now they are saying the radiator is clogged. I guess I am open to any input, I really just want this issue fixed before it causes any damage but I don't see how a clogged radiator would cause a intermitten problem like this. Thanks, Ed

 

Is the radiator very dirty? Is there any debris trapped between the radiator, AC condenser, etc?

 

When you remove the radiator cap, does the coolant appear relatively clear or is it dirty? Speaking of the radiator cap, did you replace it with a new one?

 

Is the car actually over heating? Just because it spews coolant out of the reservoir cap, that doesn't mean it's over heating. It may just need a new cap.

Is the high speed fan coming on? It should come on around 220f. If you are stuck in traffic and the high speed fan isn't working, then the car can overheat.

 

yes it is definately overheating. the wire harness going to the fan relay has burnt through the plastic in the fuse and relay panel on one of the the relays. they pulled the water pump and it is ok. they are going to check the radiator tomorrow to see if it is flowing or not. i got to talk to the tech today and he said that he filled it back up after the lane spew and could not duplicate the issue ' but the fans stayed on full blast until unplugged. as soon as he disconnected the fans; temp jumped up. i personally am thinking there is a short in the wiring and (i am doubting they did the thermostat) after hearing it was pulled out and tested by the service adviser' but then talking to the tech that said he did not pull it out yet but just checked water pump.