engine running cooler after blocking the grill
 

like the tittle says, i blocked the grill on my cavalier, and now the opposite of what i was expecting is happening. instead of running a bit hotter, it is running cooler. now i understand that the stock temp gauge is not that accurate, but normally it sits a little above 195*, but now its about the same distance, but below 195*. what could be the cause of this? it does have an air dam attached to the bottom of the radiator to direct air upwards to the radiator, but the fact still remains that there is less air flow. this has me stumped. i should be ordering my scangauge friday, so i will have a better readout on the actual temp. but what could be causing this?

Did you travel the same roads, and travel for the same time when you are comparing before and after the grill block? Was the outside temperature about the same before and after? Did your radiator fan turn on right before you checked the temperature after the grill block? There are many factors that can affect that temperature, and being off a few degrees is not a big deal at all. Also, you have affected the way the air flows in that area, and so the radiator could be in fact be getting a little cooler, especially where the temperature is being measured.

Upper grilles have been mostly cosmetic in recent years. It's possible it was just making turbulence that disrupted the through flow from the bottom grille.