2006 Chevy 2500hd cooling system question

[bobbytheboozer]

I have a 2006 Chevy 2500hd, 6.0 gas. I noticed this morning on my way to work with the heater on that my coolant temp went up to 230ish degrees. The air didn't get that hot after running the heater for about 5 - 7 minutes. There is plenty of coolant in the reservoir and it isn't dirty. I'm thinking it is either a clogged heater core or maybe air in the system. I haven't seen any leaks or drips from the system

Does anyone have any ideas or run into this problem before?

Thank you in advance.

 

[mjc]

Check the when you first get back in it. Mine was the gauge going bad. The needle won't be down in the fully off position. If it is wrong you to put if gauge stepper motors.

 

[bobbytheboozer]

Check the when you first get back in it. Mine was the gauge going bad. The needle won't be down in the fully off position. If it is wrong you to put if gauge stepper motors.

Yea I have an X-27 stepper motor kit. I haven't had time to install them yet.

The needles all go back to their off positions when I shut the truck off. Hopefully it's just a stepper motor.