Great information to have, Komeuppance, and thanks once again.

I noticed the hesitation is always when the thermostat seems to be opening...just before operating temperature. The sensor is, in fact, on the thermostat. I DID get a replacement sensor, but the threads did not want to go into the existing opening, so I didn't force it. I had thought to order a new one, and your post prompts me to do so, though I will go through RockAuto, because I haven't had any bad experiences with them.

The sensor I bought was from Advanced Auto.

For those following my daily life~saga: the washing machine mysteriously started working again. Good thing, too: two weeks of no clean clothes got me down to a pair of skivvies, a tie-dyed t-shirt and one sock.

THERE'S a visual for your morning coffee.