09 4.0 Temp issue

Hey guys newby here and have a question. Have approx. 50K on my 2009 toyota 4.0. So far been very good truck but just this past weekend my temp gauge jumped up to midway on the indicator?? It is stable but it has always been about the 1/3 range when fully warmed up. I also noticed the engine heats up very quickly now, (within 5 minutes) its at the half way point on the qauge. (It used to take 15 minutes to heat up)

At first I thought just an indication problem (sensor) but cked with ohm meter and within spec. Now i am suspecting a failing thermostat.. Has anyone experienced this prior???

 

Sounds like the T-Stat... I would inspect it but also have a replacement available while you have the other one off the truck.

Check that the valve opens between 176 to 183 degrees F.

Also, when's the last time you changed your coolant? You're coming up on 60k so now would be a good time.

 

Interesting, but on my 09, the standard behavior is with the temp gauge at halfway and taking about 5 minutes of driving to get there. Been that way since new.

If you are concerned, you might consider a Scangauge or Ultragauge so that you can see the actual water temps. According to my Scangauge my stock temp gauge gets to about halway at 180 and has stayed there at least through 205 (highest I've ever seen it) and doesn't move.