Water pump, or thermostat stuck closed. Or even frozen coolant if its a weak mix. Is anything blocking the airflow to the radiator? Its a Ford that has lived 105,000 miles more than it should have, tell it its a good car and shoot it to put it out of its misery!
I just noticed you said the coolant was bubbling...does it look like theres a scuba diver in it? (air bubbles coming out) You probably have a blown head gasket.