Cadillac: Coolant Leak, cadillac eldorado, coolant leak

Question
I have a 96 Cadillac Eldorado 4.6L V8 which is loosing coolant without showing any visible signs of where its going, it does not appear to have any external leaks and it also does not appear to be leaking thru the head gasket in to the oil. I fill the radiator on Monday and by Tuseday afternoon all the warning lights come on saying its empty and the car is overheating.

Ive heard it could be the water pump and that was my 1st guess, but Ive also heard it could be the intake gaskets.

I greatly apprecciate any advise you could give me regarding this.

Answer
If your not LOSING it externally then you are USING it internally and is being burned by the engine. You need to perform a radiator pressure tester to see how much radiator pressure drops when you add approx 15 lbs of pressure to the radiator cap opening on the radiator.