The sensor is failing intermittently. Replace it. After that, if the temps are low, replace the thermostat.
Thanks for the great reply, I guess it is still reading almost exactly in the center, I have already narrowed the problem down to being the sensor only, however I can get a thermostat quite cheap from my local parts shop and the best thing is that they only have original AcDelco replacements. And as I plan on taking the car to someone who had a nice garage and hood tools I think it would be better to just get both of them done, as another trip over to his place is something I don't wanna do. Primarily because I just love to work on my TB myselfI agree with my good friend Mooseman. Your gauge is still reading a bit lower than it should. (It usually reads about half a tick to the right of center.) The gauge is not linear, so straight up and down versus half a tick to the right is about 20 degrees difference, believe it or not.
If the thermostat is bad, it is usually a long term trend left of gauge center.
If the sensor is bad, it is usually a bit intermittently up and down, especially on the highway. Do sensor first, then see if it is fixed. Then do thermostat.
The reason we usually recommend both at the same time is that they are side by side on many years, but 07 on, the sensor is in a completely different spot. This is where the experience of this forum will help deciding which one to try first. No guarantees, but I am also guessing it is a sensor problem.
Golden words right hereThat I can understand completely. There is a great feeling of satisfaction after a job is done right, and I don't care what anyone says - it always seems to run better when something is fixed, even if it was just the rear speakers or the passenger window regulator. (Did both last weekend.)