I'm getting on freeway today, with AC on. After merging into traffic (uphill) and achieving about 70 MPH, I glance at my instruments and see the water temp at redline, my SG2 shows 270degF as the peak temp. I turn off ac, throw it into heat, windows down and exit. Just then the temp drops like a rock and stabilizes.
So now I'm changing my T-stat, but should I expect and repercussions from this event? The truck hadn't been on more then 5 minutes and maybe 1 minute that I saw the temp in the red. Anything that I should be looking for?