Went for a spin over the last several days, weather near 90 degrees. On my aftermarket gauges the temp got up to 180 degrees and no further even in stop and go traffic and no fan on (manual fan switch only). Each time I noticed a quick drop from 180 to about 175 then slowly return to 180. At first I thought there was a loose connection but everything checked out. Used a non-contact thermometer to confirm the temps were correct. Is the thermostat actually cycling to cause this fluctuation?