coolant temp gauge acted up.
 

I was driving yesterday (90F weather) with AC half way blasted and I noticed that when I got stuck in a little traffik, my temp gauge went to RED and lighted up for a few seconds. So I kept my eye on it for a while and it went back down slowly on its own. I finally got to my destination and popped the hood. Nothing seem to indicate any overheating since I did not smell anything burning or extreme underhood heat. I drove around a little more keeping an eye if it returns but never did. Anyone had this happen to them? thanks - Rod

You need to replace your thermostat most likely....

^^ that's what i suspect also..guess i'll look into replacing that along with the water pump soon. For the meantime it has not act up again, but i'm keeping an eye on it. Thanks

If you press for time, just flush the radiator $24 + $1.99 (BMW coolant + distilled water) and maybe 1 hour of labor. You may have some crud in the coolant floating around clogging the thermostat from time to time.

^ I'll give that a try thanks.