temp gauge fluctuation

[RVTRKN]

I ran my truck cold in the morning, which I normaly don't do. When I looked down at my water temp, after running 20 miles. I noticed the gage was moving from 170* to 200* and then back to 170*. The ambient temp was 62* with 85% humidity. ???????????????????????????????????????????????? I will check later today to see if it still does it in warmer temps.

 

[PFranzese]

Mine does that as well, I noticed it since new and 20K+ later it still does it. I think its just the thermostat opening completely and the full flow then reduces the temp back towards 170-180. I see this twice a day, leaving for work in the morning and leaving for home in the evening. Never had a temp issue even while towing in the mountains so I just chalk it up to how the thermostat works.