Hi. I have an '04 Ford Explorer. On Monday I was on a long trip, and it overheated/steam/boiling/shut itself down just as I pulled off the highway. I have a Garmin Nuvi w/ ecoRoute HD and right as it was shutting down, the temp registered at 330 degrees (it had shot up from around 198 pretty suddenly). It took over an hour and about 8 bottles of water before it would start again. A mechanic pulled over to look at it and told me to add the water and let it sit for a while, so that's what I did. Anyway, got to my destination with no problems, and took it to the mechanic on Tuesday (since it was after closing time when it happened). Took it in to the shop, and they flushed the radiator/changed the oil/said it should be good. Drove it for the rest of the day on Tuesday and it was fine. Wednesday night, I ran to the grocery store, and on the way back (at about 7 minutes drive time), it shot from 140 up to about 270. I pulled over, and it dropped back to 198. Thursday, the same thing happened. At about 7 minutes drive time, it shot from 140 to 270 and then dropped to 198. No matter how long I drive it for after that, it sits at 195-205 degrees. Any ideas? I've stopped driving it for the time being and I'm taking it in again on Monday and would like an idea of what I'm looking at. Thanks.