Temperature Gauge Sticking?

[Wildchild467]

My Temperature Gauge has been sticking a little bit lately. by sticking i mean when i am driving and the temperature gets up to 200 or a little over (because i have the winter cover on and like the engine to get good and toasty for complete combustion) and then i let it idle to cool down the guage does not come down that fast after i open up the cover. It seemed to me that it should come down faster than it does. SO.... when i was sitting there waiting a few minutes to let it cool, i shut off the accessory switch and turned it back on. to my supprise, the temperature gauge droped down a lot (15 degrees or so). So my thought is that the gauge is sticking and when i shut the power off and turn it back on, the gauge find its new place to read the correct temp. I know these trucks are sensitive to grounds.... could that be the problem? i wouldnt think it would because the temp gauge does not rely on a ground does it? Could it be a grounding issue, gauge issue or sending unit?

 

[hof3414]

Since it has got cold out I have noticed mine has been sticking and jumping around alot more than normal. Normally mine gets up to temp then stays there for the most part. I don't have a winter front so it has been running colder, but it kinda of dances around and even jumps when I hit the throttle. But overall truck has been running fine with cold temps (25-35 degrees) and heater works good.

 

[Wildchild467]

mine did it in the summer too. but the coolant temp didnt get that hot... just warmer when i pulled the long hill going back to the house. so i would let it cool a little (per TM) and it would stick a little then too.

 

[Heavysteven]

I would bet sending unit

 

[rchalmers3]

My thoughts are:

a) Poor grounds affecting the operating voltage of the gauge
b) Power voltage fluctuations affecting the gauge
c) Actual mechanical problem with the thermostat
d) Mechanical problem with gauge

My recommendations are to tap the dash when you feel the the gauge is reading too high, to see if the needle settles with some moderate vibrations.

If that doesn't make a difference, measure power and confirm grounds when you switch the power on and off as you have related.

If you suspect a sticky thermostat, you may want to install a temporary second gauge for operating temp comparisons before replacing the t-stat.

Rick