My friends 3.8 Windstar is losing coolant, but it is not external. No apparent leaks under the frame or around the hoses. None leaking behind the firewall. Coolant is just vanishing in thin air! It has been fine for about 2 weeks and all of a sudden this issue came back. Anyone have any clues. There are no apparent signs of HG failure either. Oil isn't milky. The van has been starting up roughly though. But no smoke out the back, or even steam coming out the rad when the engine overheats. I'm completely stumped, and these are good hard-working people with no funds for a major fix. If anyyone has had this issue of mysterious coolant dissapearing, please let me know the outcome of your situation. Thanks.