Howdy folks, new over here and looking for some suggestions. 2003 Ranger 4.0L

Last couple days I noticed my temperature gauge much lower than where it normally runs at. I live in the great white north so winter and extreme cold is nothing new here.

From an overnight -25C type night when started the temp will slowly climb but not to anywhere near the normal level of the gauge where it always has(and did just a few days previous). Once I start driving it will very quickly climb to close to the normal area then after driving a short while will gradually start dropping down to near the bottom of the guage display area. It will then fluctuate a bit up and down but will not return to the normal levels I am used to even in these teeth chattering conditions (owned the truck since 2007 and never had this happen).

Coolant levels good and haven't changed.
No signs of any kinds of leaks.


First instinct was thermostat sticking but then shouldn't I expect some issues with the interior heat levels as well? All seems normal here as it warms up nice and consistent inside and blows lots of heat.

Thanks for any info/suggestions.

Darren