Sounds like the problem is loss of coolant, but the cause needs to be determined. Based on your observation of liquid under the radiator, I would recommend having your mechanic perform a cooling system pressure test. If a leak doesn't show up right away, he can add dye to the coolant, then he will look again hours later with black light.
A leaking head gasket can also lead to overheating due to air pockets stopping coolant circulation. Your mechanic can test for that with a special tool held over the coolant overflow reservoir.
Tuesday, January 26th, 2010 AT 9:14 AM