Thread: Coolant tank leak

I have a 97 grand prix 3.8L that runs fine and does not over heat. I know how coolant works and how the radiator cap works but a few mins after shutdown my car starts pumping coolant out of the overfull onto the ground. I need to understand why? I know it should start drawing it back into the radiator after it starts to cool but instead its like I can hear a slight clicking noise then it starts to pump it on to the ground, and in decent amounts. I know its not my cap i have already tested it. Ive replaced the waterpump and flushed the system, is there a switching valve that isnt working? or what? Let me know what you think.
Thanks

yeah 97 was the only year i know of that they put the overfull tank on the drivers side. I found out that it was the radiator, it had a small crack on the plastic molding on the front side, so i couldnt see it until i took the mounting brackets off because the oil cooler is in front of the radiator. And the crack was just in the right spot to make it look like it was coming from the overfull. So i got a brand new radiator for $60 because i know a guy who owns the company so its all good now. thanks for your thoughts.