What does a bad head gasket do?

My head gasket is bad, I know because when I turn the car off, coolant is coming out right where the intake manifold connects to the block. So what problems would that cause performance wise?

actually your intake manifold doesnt really connect to the block, it is bolted to your heads, and it sits ontop of the block. a good idea to go through and put nex gaskets it, get the heads cleaned up, chanck the valves, intake refinished and so on while your at it.

It could blow the engine. Antifreeze in oil doesn't make a really good lubricant for bearing in the bottom end.