I had a similar problem and it was that the washer on the rear bleeder valve was bad, and it caused a small drip and it smelled like antifreeze.
My temperature ran a little high when this was happenning around 190-195, now it 183 -186 even after driving for 3 hours non stop at 90 plus degrees.
You may also want to bleed your coolant system to make sure that their isnt any air trapped in it. One side of the coolant reservoir should be full, and the other one should should be about half full and to the mark indicated on the reservoir.