Don't worry, starting with a cold car, there is no threat of pressure or impeding geyser :)
Good points were brought up, hopefully there is not a massive leak or plug. But maybe its a sequence of events: recent ish work, defective t stat gave up (easy 1 out of 20 for your car), you replaced t stat but maybe not a good purge.
You added coolant to the reserve tank not to the radiator, I say this because you got cool air when you turned on the heater and the reason for that is the coolant is low in the radiator. The pump is fine. The other thing is the cooling fan, is it coming on? Turn on the A/C the fan should come on right away no matter if the A/C works or not. I think that is where your problem is.
When was the last time that the cooling system was drained, flushed and CLEANED with one part powered acid cooling system cleaner. A 12 year old car is way overdue.
**You should always fill the radiator first to the top when the engine is stone cold. Fill the plastic coolant recovery reservoir 3/4 full at the same time.
Being an 02, it could be your radiator, heater core or head gasket. You need a qualified mechanic to check out your car even if your 60 mile from home.
you have an air lock..or new thermostat was put in back wards ,,,install a 5/8 flush T in the heater hose that will make it easier to get the air out
air in system.
Back in December of 2013 I had my timing belt and water pump replaced on my 2002 Chrysler Sebring LX (sedan, 4 cyclinder, 2.4L dohc) and just about 3 days ago my car started overheating (while I was out of town an hour away!!!). Luckily I still fall in warranty but I am not sure if the water pump could be malfunctioning. I still have warranty until December 31st so fingers crossed. I opened my coolant tank and it was low, I always have coolant and water in my trunk because of last year with it overheating. So I added a half and half mixture and let it run for a couple minutes to circulate and let it sit (I was on my way to dinner with my boyfriend so we went inside to eat). We had hoped this would work but it didn't, it began to overheat again after driving a mile and a half. So now we know my coolant isn't circulating or that's how it seems. So we get my car back to his place and go get a new thermostat hoping it will be a cheap, easy fix, but it still over-heated after 3 to 4 times around the block. Now I'm in a sticky situation because I'm 60 miles away from my normal shop that I use. It is a larger tow fee and insurance only covers 11 miles. Also, I tried turning on my heat to help cool it down, only cold air comes out even when it says it is overheating. I am just trying to pick the most cost effective thing to do, I don't want to pay to have the repair done when my shop will do it for free, but if doesn't seem like it could be the waterpump let me know.
