Sorry, I forgot to mention that the high temp was caused by a blown fuse on the a/c aux fan. I had by-passed a faulty switch and wired the fan to stay on using a 15 amp fuse which I have since replaced with a 20 amp one that seems to be working better.

What I'm wondering about is why this piston got stuck? Curious that it happened less than 2000 miles after I started using ULSD. Did someone not put in enough additive to bring the lubricity up to spec? Or was it just a coincidence of old age. Maybe I should start using a fuel additive myself since I'm over 200,000