Is there a direct relationship between the idle RPM and water temp? Last couple times when I was crawling in the stop and go traffic, my temp gauge moved to 3/4th to the right. At the same time my idle RPM went up from 1K to 1.2 to 1.3K. I wonder the increase in water temp was the result of the increase in RPM or vice versa? Or could it be the length of my throttle cable changed in the intense heat under the hood in traffic? Or could it be entirely something else?