Regularly look at your radiator. Allow your car to work for the bit then turn it off and pop open the hood. If the car is running, tend not to open the radiator.
https://www.youtube.com/watch?v=1aPd8ZemaIo
http://vidmax.com/video/108026-LED-Outfitters-Are-You-Currently-Having-Car-Problems-Try-The-Following-Tips