temp gauge fluxuates?

[cwshupe]

I have 94 ford ranger with a 4.0 litre. I install new reman engine 7 years ago. Lately i have noticed that my temp gauge fluxuate, not to the "H". With my heater on, the air temp stays the same when fluxuating. The 2 things that might be is bad gauge, or sensor. But, I would like a second opinion.

Thank for any information.

 

[v8nick]

Stock Ford gauges suck. It is probably just the sending unit.

 

[Original_Ranger84]

Probably just a bad sending unit... My 84 goes all over the place, including being well above hot even after 1 minute of driving sometimes.

 

[dennis461]

Start cheap...go slow...
Make sure the water levels are correct.
Check fan spinning with engine warm (fluid clutch, right?)
Find the gauge sending unit, replace it.
Change the thermostat.

Any water on the ground?