I have a 2007 Lacrosse, 3.8 Series III, with 42k. I have a Scan Gauge to monitor engine functions. I have never changed the thermostat, guessing that is an OEM 193. Temp very seldom gets above 174, although, it will fluctuate between 168 and 210. I completely lost heat a few days ago (not fun with -30 wind-chills). Everything seemed to be working good except for the erratic temp. I did fix the problem by back flushing the heater core, something I am now going to replace next summer. Heat seems to be working fine, but wondering if I should replace the stat?