I had the same problem a while back, took it to my fav nondealer mech, he kept it for three cold mornings, couldn't figure it out. He recommended taking it to the Lincoln dealer. Within minutes they diagnosed the problem. Leaking valve cover o-rings on #5 and #7 cylinder, 700 bucks and they would fix it. I said don't touch it I'll take it home. Pulled those coil packs and guess what, there was oil half way up the boot. So I changed the O-ring gaskets and cleaned the oil out of the coil boots and hit the starter. That was 40 K ago and still going strong. Hope this helps.