I talked to Ford and took it back to the dealership. It was the waterpump. Ford is giving me and the dealership some problems about the warranty. Turns out that when I had the last WP replaced in Oct, it wasn't under warranty, so the dealer covered the bill. Therefore, this time Ford expects me to pay for the pump. I thought that each time the part was replaced, the warranty would start over with a new 12 month/12K miles, but Ford said no. I'm going to get a call from the dealer after he talks to Ford tomorrow. I'll keep you updated on how it pans out. Might be driving something other than a Ford in the very near future!