What the heck? Why would this gauge peg then go back to normal? I suspect faulty wiring to the gauge, rather than an actual overheating. I checked the radiator after the engine cooled. It needed about a quart, and I put more in the resivore. But that's not really all that low.
The outdoor temperature was around zero anyhow. The only other thing I can think is that the thermostat was momentarly stuck, but I had just driven 30 miles with no problems.
Anyone have any suggestiond?
Thanks