07 cobalt temp. Fluctuates from 197 to 215. Random. Cools down at high speeds or with AC. On..

That sounds normal. The temp sensor should turn the fans on at about 212 and cool it to 190 then it rises and fan turns on. when A/C is on there is a fan that runs all the time, on the highway there is air moving across the radiator and engine so it would cool it doen

The above answer is good. Also it may indicate the thermostat may be on it's last leg. When did you last check the level in the cooking system? Make sure it is filled correctly and the correct amount of antifreeze is in there. Also after 7 years, it just may be time to change the butter flies and June Bugs that gum up the radiator. Use a hose and spray the radiator then a soft brush to remove the bugs and keep the air flowing through it.

My 08 Cobalt temp runs between 192-215 as well and from what I was told, with these type of EcoTech engines it is normal.

My 2007 cobalt engine temp while driving will fluctuate from 181 to 189 then go up and down, Drove from florida to North Carolina stayed pretty regular at 183 until the last two hours of the trip noticed the fluctuation, it got cold so I put the heater on and the temp gauge started going higher, before I left florida I wanted to put some new coolant in the system, couldn't get the petcock loose so pulled the lower radiator hose once it stopped coming out, rescued and filled coolant little at a time until I got I just above the full line let it run, put the heat on while running everything went fine, but not alot of purging came out of the overflow tank..drove it a couple of times before the trip, nothing happened until then, answers?