[j3rt]

My Zetec was overheating, I did a lot of commuting in that car. Guelph-Toronto daily. After replacing a couple parts the true culprit was found. There was a 'T' hose that failed. The coil inside, and the hose were colapsing under the draw of the coolant, so when it started to heat up, and I threw the AC on, it actual caused a greater vaccum and starved the engine more.
Anyways, found it, sourced it, and the car ran happily every after. It was an '02 with 260K. Figured I'd add my experiance, because finding it took a couple months. I'd tell my mechanic, he couldn't find anything, the car had to have been really really warm up, the hose had to be hot etc.