I've got an 07 Dodge 6.7 with approximately 76,000 miles on it. Recently, I was pulling my Toy hauler up the Grapevine hill in Calif. The Toy hauler is a 23 foot Weekend Warrior which loaded probably weighs in around 8,000 to 9,000 pounds. I noticed the temperature gauge begin to head towards the 245 degree mark and the fan make some different noises. The truck never made it to the 245 (hot) zone because I adjusted my speed from 55 to 50 MPH. The temperature outside was around 95 degrees.
When I got home, I took the trailer back to the storage yard and I was travelling approximately 70 with the trailer in tow and the fan came on again. I have never heard the fan come on before and wonder if something could be wrong with the fan.
If anyone has some ideas, I'd love to hear them. A buddy that was behind me pulling a 35 foot fifth wheel didn't have any heating issues and told me that the truck I have shouldn't be reaching close to the 245 degree limit. The only difference between his truck and mine is that his is a 2004 with a Banks system on it and mine is a stock dually.

 

Did you scan the truck for any stored codes?

 

No, I didn't. I don't have a scanner. I thought the check engine light would come on if a code came up. I'm not at all familiar with diesels. This is the first one I've had. What am I looking for. Thanks.