Water Temperature while Towing

[SS396]

I tried a search on this but couldn't find anything, I am sure this has been asked before.

Last weekend we towed our new 8-9,000# 5'ver for the first time and noticed that the water temperature indicated 210 degrees consistently. Driving back and forth to work it usually indicates 195 degrees, as near as I can tell anyway.

Now I realize the gauge is inaccurate, but a 15 degree difference, while towing, seems odd especially cruising down the level freeway. A possible explanation is that while towing the second thermostat is operational, while driving to work, only the first is operational.

I wasn't too worried about it because the Duramax pulled the load like a dream, more curious if anything.

Should I worry?

Thanks.

[Lone Eagle]

SS396 (402), Mine runs at 195-200 empty or towing this time of year. I did see some 210 last July pulling my trailer up three miles of 6%. The engine temp came down real fast after I hit the top but it took several miles before the trans cooled. Later! Lone Eagle ;)

[peachin]

My 2003 Duramax/Allison runs between 200 and 210
mostly 210 while towing. How does the Air Conditioner affect this.

My prior 97 6.5 was running hot if it hit 210 while towing.

[Dave]

I have never seen much variance in my cooling water temperature. Runs 185~190 most all the time even towing 12,000 pound RV. I have never seen it over 200 even in 100 degree weather pulling the RV. Now when it's below 35 out side I have seen where the water temp goes up to 180 then down to 160 and back up and back down when running empty. It just cycles like that in the cold empty.

Trans temps run about 180~185 most of the time when towing in summer. On a few grades of 6~7% towing I have seen it hit 200. But temps climb the fastest when backing an RV up hill or a long way, have hit 210 backing on a few occasions and 220 once.

[chuntag95]

I see 205 in traffic pretty regularly. See 200 on the tranny too. Run synthetic, don't worry, have a job, wife and kids for that. :D Traffic seems to be harder on my truck than towing. :rolleyes:

[gardnerteam]

Always under 200 no matter what, including towing 20,000 lbs across California desert at 95 outside temp (cool day), same load over Cascades and other ranges. All stock except for deep Allison pan and Transynd. Stayed the same in 4WD off road heavy use in Southern Mexico with temps well over 100, which my previous 6.5 would not do. GM finally got the cooling right.