2003 Dakota 4x4, 4.7 litre

The interior gauge is riding just above 1/2 way mark, if I stop at a set of lights for a few minutes, the gauge somewhat stays there, but once I start moving again the gauge will move up to about the 3/4 mark, then about a minute later will start to drop back down to just above the 1/2 mark on the gauge.
From what I noticed in the past it never rised above the 1/2 mark.

I have picked up a new thermostat, (not installed yet), coolent looks a little low, and is more on the water side then being 50/50. Would it be as simple as the ratio not being right?

 

Does the water pump have any play in it? meaning can you grab the fan and move it at all? I had the same problem in another vehicle and it turns out that the water pump was going out slowly.

 

Changed the Thermostat, and the coolent.
Thermostat looked fine/clean, coolent was needing to be changed. Everything seems back to normal now.

 

Did you flush it as well?