I have a 06 2.7 Charger I'll give a little background on it first. Last year I had the head gasket replaced at the dealer and which ended up creating a lot of problems because they didn't do it right, Well after all the complaining about it and them replacing the water pump, idler pulley, and thermostat they replaced the head gasket but now when I turn my heater on my temp gauge will go from normal position to one line lower towards the cold and will stay there until I shut the heat off. I have no leaks, I've replaced the upper and lower radiator hose, and the two heater core hoses which are all hot but after shutting the car off tonight I touched the lower rad hose and it was cold. I'm at a lost. Could they have put a 190 t-stat in instead of the 180 and that could be why the gauge drops? Heck I could use some HELP!!