I have had to add antifreeze (1 cup weekly) to my overflow container.I didn't mix it 50/50. Now I'm on my second gallon but start using the old type of antifreeze. I don't see any leaking hoses or drops on the ground. No white smoke or no water droplet on dip stick(oil). Where could it be going? Some one said 2000SAturns have this problem.Could it be my headgasket? Car has 60,000 miles.

 

1st: Antifreeze should be mixed 50/50.
2nd. I hope you didnt mix the dex-cool with older type of antifreeze.
3rd. Check water pump seal or weep hole. But it does sound like you may have a leaking head gasket. Dealer can pressurize system and find out where the leak is. Myself, I Think it would be worth a service call.

 

I agree with Darrell.