07 Q7 4.2 Coolent overflow out of pressure tank
 

My 2007 Q7 4.2 started to overheat to 3/4 off & on for couple of weeks and then it went all the way to red. So I order and change out the thermostat this past weekend. All seem to be good, it drives great, didn't over heat. But, after driving it and stopping the pressure tank start to overflow and pushing out coolant from the overflow. So I tried to burp the system and it didn't work. I also flushed the system and burp it again. But I'm still having the same problem. Water/coolant is still coming out of the pressure tank overflow after stop the engine. Car is running great and heater works great. It is not over heating. Please does anyone have a solution for problem? It's driving me nuts! I'm trying not to take it into a shop. Thanks

Well you probably overfilled it, If thats the case dont worry about it.. its common to puke out coolant out the overflow tank after changing out all coolant, liquids expand with heat.. but to be safe I'd check coolant levels after a tank of fuel or so and make sure that it didnt burp a bunch of air out and now its underfilled.

I have been checking it after every drive. It not being overfilled. I wish that it was that easy. I wife said it was dripping at idle as she was waiting for son to get out of school. It could be the cap or pressure tank or a cog some were. But it's not over heating or running rough. It's crazy, it didn't do this before it start overheating. All I did was change the thermostat.

coolant is being pushed out over flow anyone know why
 

Im having the same problem with my 2007 q7 my coolant is being pushed out my over flow it started outta no where i also had to change my pcv value cause I thought that was the reason it was intaking to much air and its was whistling but that nor bleeding the coolant system worked