Sooner or later it would come down to the water pump. First overheating episode was determined to be due to a faulty radiator header tank cap. That was replaced and no more overheats for several weeks. Kemudian, in Overheating - The Sequel , we had to stop on the side of the road and call for a AAA tow.
So we decided, based on the behavior we saw in the second episode, to have the cooling system flushed and the thermostat changed. We had already tested the twin radiator fans and found them to be working properly (easily done, just turn on the A/C.) We were thinking that the cap was where the leak was still occurring.
Upon dropping off the car at the shop, I noticed a trail of fluid on the pavement from where Kim had driven in then backed into parking space. I had her release the hood and I took a look. No leakage from the cap area, bagaimanapun, there was a growing pool of coolant at my feet... "This isn't going to be good.", I thought.
Sure enough, the shop called and said that the O-ring for the water pump was leaking. So we had them replace that too.
We picked Piggy up this morning and her temps did fine and no leaks thus far. We'll just have to keep an eye on her. Such are the joys of driving a 15 year year old car.. along with other, and true, joys such as no car payments and no costly full coverage insurance.
Oh yeah, we'll keep our AAA membership in force and pray we always have cell signal when we need it!