Temp gauge moving

[Colorado Cowboy]

Good Morning,

I can't find anything related to this, but if this question has been asked and answered please just point me in the right direction.

I have a new problem. My temp gauge keeps moving back and forth while driving. I have changed the Thermostat and sensor. It does not show it as overheating, just constantly moving back and forth from where it should be sitting, up about 10 degrees and back down.

Any ideas?

I appreciate the help!
Rick

 

[Daw14]

It’s normal,your house thermostat has a range when you set it for heat ,like it comes on at 70 then goes to 72 before it shuts off. There has to be a temperature differential,it just won’t stay constant. May not be best explanation but I hope it helps some.

 

[MADDOG]

How much is it moving? It should not be moving back & forth across the entire gauge range from COLD to HOT all the time during normal operation.

Some movement is normal and changes in coolant temperature happen due to airfow, ambient temperature & truck mechanical system operation such as:

1. Engine is warming up & thermostat opens.
2. Ambient temperature rises, coolant temperature rises, a pre-set temperature limit is reached and the cooling fans come on.
3. The reverse of #2 when the fans are running the temperature falls.
4. Slow speed vs. highway speed in warmer ambient temperatures will result in an increase in temp during slow speed and a decrease in temp as speed & airflow increase.

 

[Colorado Cowboy]

I've had it for about 16 years and this has never happened before. It is not like when you are towing and go up a hill, it is constantly going up and down. Like I said, it is just a small amount, never going above about 10 degree difference, but has never done it before. I am wondering if the gauge is bad or something else?

Thanks!

 

[Daw14]

Maybe it just started to work,and never has before now?