My Dad recently rebuilt the engine, complete with new bearings and gaskets. UIM checked good too

Checked...or changed?

Checking is only as good as the person that poked that EGR tube area with a pick. One spot may be good...one might be ready to fail.

Don't know which, I'll have to ask. Thought he said he checked it and it "was a good one". Also, I checked my water and it is perfectly full, right at the line and everything. is it possible the leak suddenly stopped, or are we looking at a different problem?

Dad tells me that the good and bad intakes had different part numbers on them? he says the one he put on was one of the good ones, and he also checked the walls of that bad spot to make sure it wasn't going. So the problem went away and the water is staying still. Is it possible the leak was temporary, or maybe I had too much water to begine with? every time I start it up, I'm expecting to see that water vapor blowing up on the windshield again.

just for the heck of it, when the engine is COLD, pull the radiator cap off and check the level of the coolant inside the radiator. Is that full also? You said that the coolant was full up to the line ( on the tank I assume ) but you didn't mention if you actually checked the level in the radiator.

Unless the water vapor was the AC evap area not draining like it should... I doubt this is a one time thing.

BTW.. there isn't a better part number on the UIM'* to our knowledge. The APN UIM is reinforced with a metal sleeve and that is the only one I know of that is "preferred". But we regress..if you see a major coolant drop off in the future..that'* the UIM

Yeah I checked the radiator level too, as well as the overflow. Both are good. I check it everyday, cause I'm all wierded out about this thing. Water level is still good, but the problem has not returned. I don't understand the "AC water evap" area thing at all

The evaporator and heater core are located in the air ducts under the dash. When the evaporator gets cold when you run the AC, moisture from warm, humid summer air condenses on the evaporator coils and drains through a tube to the outside of the car. If the drain tube becomes plugged, condensate can build up and find its way to the inside floor of the car. It should not, however, smell like coolant. The condensate starts out as pure water, and may pick up any dirt or dust it finds on the way to your carpet, but coolant should not be present.

If you have coolant leaking on the inside of the car, the only source is the heater core, unless coolant is spraying through an opening in the firewall somehow, like from a leaking heater hose at the heater core. Possible, but not likely.

Oh I see. problem is, the AC on this car has never worked. Besides, problem found. The core finally busted loose and was leaking like crazy all over the floor. I removed it and there was a sizable leak. Problem solved. It was a bear to get out though. I'll be putting it together today. thanks for the help!

glad to see another problem solved