First time poster here. Little background. Have owned only Ford 7.3's and 2 6.0. Made the change to the 6.7. (currently 7000 miles, engine light once at 2500 miles. No DPF messages)
Now to my question: With truck at operating temp, is anyone seeing their temp guage fluctuate from around 175 (3/4 way to 200) while driving 30-50 mph to about 215 (1/3 way to red (245)) at 75. At 75, it sits just a hair below 200 about 50% and around 215 the rest. Regen should have nothing to do with this, should it? Is this normal in the 6.7 to see this much temp fluctuation. I am used to when a diesel gets to temp it stays there. Had the reflash last Friday (so I'm told, no mod sticker, took all of 10 minutes, apparently did not follow TSB instructions). Sorry for being long winded.

 

one of the trucks i drove around for a day did the same thing. I thought it was kinda weird but i wasnt worried about it as it never got HOT or anywhere close.

 

yes the temp guage moves, don't know exactly why but every one i've had does it. as long as it doesn't go to red

 

My new 6.7 does it, and my 2002 5.9 does it. Especially under a load. I was also concerned when my 5.9 done it but, it now has 108,000 miles on it with no problems. I geuss it's just the nature of the beast.

 

I have the Commander digital temp gauge on my 6.7 with 6 spd auto. The lowest I've seen it run after warm up (cool day, AC off, mid 50's temp, 55 mph with no load) was 200 degrees. I've never seen it go higher (yet) than 215 and that was on a really hot day pulling a 10K trailer over 12,000 foot passes in the Colorado mountains with my foot buried in the firewall.

I see it fluctuate occasionally between 200 and 210 when I'm running around town on a hot day sitting in a lot of traffic.

2300 happy miles so far with No CEL/MIL yet

 

I never seen mine hit over half way!!!! from city traffic in houston and florida during august, and from runnin around doing 85 mph constant, even hit 100mph. She runs perfect on that end.

 

The guage in the instrument cluster is actually adjustable if it bothers you! The dealer can change where it actually reads compared to the temp. It isn't anything you can do yourself, sorry. Some dealer techs may have never done it before, but it is possible. At least it was from about 1993 to 2005!

 

Good info. Sounds like this is nothing to worry about.
MtnTrucker - Actually I went over Monarch pass 2 weeks ago pulling 10k and it never got over 215 or so.