FYI On Engine Temp Gauge

[Roy W]

My thermostats have been acting funny lately. Engine temp unloaded at less than highway speeds reads and stays around 180 degrees on the dash gauge. Turnpike speed it goes up to 205. Just for grins I shot the upper radiator hose AND thermostat housing with my laser thermal gun and after a 30 minute run with the temp gauge reading 180ish, the temp gun read 165 degrees. I haven't checked it at the 205 dash gauge reading yet, but will next time out.......Interesting

[DmaxMaverick]

That sounds pretty normal, and accurate (gage vs. IR). External component temps won't reflect the exact temp of the actual coolant and core temps. Ambient temps and heat-soak can effect the reading as well.

Your 180-205° indicated temp swing sounds typical for a 2005 under most conditions. The swings can widen as the ambient temp increases.