I have a 1994 Chevy Corsica, 113,000 mi. With a 3.1, 6 cly. Engine. It has just started loosing coolant fluid from a rubber L shaped drain hose near the firewall. Does this indicate a bad heater core or some other problem? The fluid pours out as long as the overflow tank is up to its marks, then when the overflow tank is empty it slows down. Thanks any help will be usefull.