Dave, am curious if u ever found leak. I have almost same problem with my Taurus. But mine leaks year round. No drippings on floor. Engine runs fine. No residue in dip stick. All hoses look tight and good.
I smell coolant only when stopped (engine running) after driving a few minutes. Replaced radiator already. Dealer and another garage cannot find leak. System pressure test holds.
Did get it too stop one time after I put Bars Stop Leak but I flushed it out later cuz I dont like the idea of having that in my coolant. This is b4 I replaced Rad.
Help!