Why would a 1995 Ford Contour overheat and the check engine light came on if there is plenty of coolant?

DAngelo: I had this problem with my 97 Contour. The problem was that the water pump needed replacing. The rod in the center of the water pump was actually slipping, so sometimes the pump would be functioning and cooling, and other times not, so my heat gage would go up and down. Fortunately my mechanic had seen this before. ford contours are known for their crappy water pumps you can get an upgraded pump with metal impellors instead of the stock plastic