Coolant leak 1988 325ise

[ten2doc]

Hi, the coolant has dropped out of my 1988 325ise, unfortunately it looks like a part has corroded where the pipe is fitted. Can some please tell me what the part is and how I fix it? Thank you

picture is here (sorry, I'm bloody usless with computers and can't figure out how to add here) https://www.dropbox.com/s/2mhbiavjp9tv7 ... 8.jpg?dl=0

[Cloggy Saint]

It looks as if you need a new thermostat housing