Originally Posted by PNA

It could be the head gasket. However, I'd certainly look for pin leaks in hoses, the radiator, etc. Have you checked all hose connections? The pitcock drain? A cracked resevoir (You'd be suprised but these plastic tanks can deteriorate).

You may need to run a pressure test. Hard to say but if you don't have ANY visible leaks or vapor areas it may well be internal.

Good luck. Let us know what you find out.

Originally Posted by Beaner

Dave, let your car idle in the driveway for a while I bet there will be a puddle under it... I am thinking it is hot and the overflow tube is working well. That whole antifreeze and water mixture just does not work as well in the heat as plain water.