my 1991 honda accord started to over heat recently and after a fw days of searching i finally found the source of the leak. its a hose connected to the engine right beneath the distributor and snakes back into the middle if the firewall. what is this hose and its purpose?

i obviously need to replace it and maybe the thermostat as well, im just praying that the head gasket hasnt been blown.

also quick question, the thermostat is either at the end of the lower radiator hose or the upper. in a 91 which is it?

 

Lower hose....

 

The line that is leaking is the heater inlet hose. It is the line that feeds warm/hot coolant into the cabin heater core for your heater.

The one that houses the thermostat is the lower hose, as mentioned.

 

Just like Ghost said. That's the coolant hose allowing coolant passing the heater valve and into your heater core to give off heat to the interior.

Those are prone to leak. Mine did that awhile back when I had my B1.