The Honda Civic water pump impeller is reliable and does not "fall off" like several European cars. If the water pump is failing on a Honda it usually leaks coolant and may start to make a grinding sound. Overheating may be caused by may things, a failed thermostat, cooling fan not coming on when it should or a blown head gasket. I steam coming out the exhaust and the engine running rough? If so the head gasket may be bad but it is normal for some moisture to come from the exhaust when it is cold. It is best to get this checked out to avoid serious engine damage.