ok lately my cherokee started doing something really wierd that ive never seen before.

randomly(about once a day) my "check gauges" light will come on in the dash, and right after it comes on my temp gauge which normal sits at 210 will jump up to 290 for about 30 seconds and then jump back down to 210 and then the "check gauges" light turns off and everything is fine again.
now my jeep has never overheated, every time it does this gauge thing ive checked the fluid, its always good, never low.

what could it be? i was thinking t-stat or temp sensor, or something else?

 

thermostat may be on the way out and not opening right

 

id replace the thermastat and temp sensor, just to be sure and if thast doesnt work i'd find either a new guage set up or an aftermarket tempgauge to hook up to it so u have an accurate reading

 

okie dokey