O.K. go to Autozone and borrow the Radiator Pressure Tester. It is a small hand held tire pump with a radiator cap and a pressure gauge on it. When your engine is shut off and cold, remove your radiator cap and attach the pressure tester. Pump the tire pump until the pressure gage reaches the pressure rating of the original radiator cap. Probably around 15 psi. Get a flashlight and look for leaks over, under, and around your engine. Watch the pressure gage for pressure drop. You might even get lucky and spot the intake manifold leaking this way. I have had leaks show up in the damndest places, like on the backside of the radiator where it mounts to the frame. The water pump weeper hole is another good spot. The pressure tester will help you find and/or eliminate any external leaks. If you don't find any external leaks and you notice a pressure drop, check the oil level on your dipstick to make sure you didn't fill your crankcase with anti-freeze. AutoZone will usually loan these pressure testers for free. It is well worth the effort. Please post back your results.