Ford Repair: antifreeze leak, intake manifold gasket, antifreeze leak

Question
i have a 2001 ford taurus se with 68000miles. it leaks antifreeze slowly. however the temperature gauge only ever rises to half way. however on cold days i notice steam coming out from under the hood. I took it to a local garage and they said it was the intake valve or something like that and would cost 250 dollars to fix it. however do you have any idea on what it could be and if you do how do I fix it?

Answer
without actually seeing the car its hard to say-intake manifold gasket could be leaking-what i would do is when it is cold make sure radiator is full-install radiator cap-start vehicle and let run until warm and start looking for steam or water stains on the engine look over passenger side fender behind the belt there is a timing cover they leak between the cover and the block-the intake gasket would leak above timing cover or on the other end of the engine it would be leaking above  where the transmission mounts to engine. i would have someone pressure test the cooling system and show where the leak are coming from.