04 Alero,2.2 coolant leaking

[Texasbuddie]

I have an 04 Alero with the 2.2 4 cyl. There is coolant coming from the overflow tank. I replaced he cap with no success. So I replaced the overlow tank and cap with no success. The engine does not run hot, the overflow tank light comes on sometimes while driving, but normally it leaks out the overflow after you shut the car down. Any help would be appreciated.