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?

 

sure sounds like it. fans won't come on till around 190-200 depending on your tune. only time my fans come on is when ac is on. at least when im paying attention. mine hangs around 170. you can check gage by ohming the temp sensor and see what temp sensor is seeing. the 4th gen gages are not too accurate

 

Thanks Craby but all my gauges are aftermarket Mooneyes and I opted for a 16" manual controlled fan. All set up for computer controlled fans but guess I'm just to old school! Seems I read somewhere that the thermostat on the LT1 cycles unlike the older Chevy models.

 

mine sure seems to act like old school. hangs right around 180 all the time. I have stock thermostat