I had a similar issue, lasted 2 days, then stayed on the hot side. Finally pulled the water pump and only had 1/3 of the rotor in place. Replaced the pump and no problem since. I think it was straying up in temp, fans kick in and pulled it down, fans off strays back up in temp, etc. Hope it helps.

jkr2wld
'97 LX - Vibrant White

jkr2wld '97 LX 2.5 ATX Vibrant White