I was loseing alot of coolant. I traced the leak to a rubber elbow located on the firewall just above the exhaust pipe. This elbow goes into the firewall but is not connected to anything inside the engine bay. Should this elbow be connected to a hose? I will double check, but I dont think that it had anything to do with the heater core. There is not a whole lot of pressure coming out of the elbow. I have a 1994 Cavilier. If pictures are needed, I can get some for tomorrow. Thanks for any and all help.