I HAVE A 2003 BMW 325 XI.

I recently had a low engine coolant light on my dashboard. I waited 12 hours after driving to add coolant (prestone 50/50, adding a little bit of water). After I filled the reservoir, I waited about 3 hours until driving. I started the engine and everything seemed fine. Until about 3 miles out, my engine temp was rising to about red. I have no clue why this is happening. I'm not sure if it is because I didn't screw the cap on tight enough, or maybe added to much coolant. It only does this when I add coolant. Any help?