07 ls 2.9
 

I have 30K+ on my LS and it has developed a heating problem but not overheating.
The temp gauge used to ride between the 1/4 and 1/2 mark for the first 30K miles then started to fluctuate up to half on the gauge when I came to a stop light and then would go back down when I took off.
I have put in a new thermostat, water pump, clutch fan, radiator, temp sensor and no change.
Took to dealership and they stuck a 195 in it and made it worse so I have taken out the 195 and replaced with 180. It now rides at half and will fluctuate a little. It is in the 20's at night and 50's during the day, should not be indicating at that range.
Have changed out the Dexcool to Prestone and no change.
ANY ONE HAVE ANY IDEAS...........