Okay, please forgive my ignorance. I really know nothing at all about cars, but am trying to learn.

Here's the deal, I just bought a 1985 760 turbo. It has a few issues, but I got it a a decent price.

It has this silver metal looking hose thingy that looks like a dryer exhaust hose on the left side of the engine. I think it goes from somewhere under the turbo unit, (maybe) to somewhere on the back of the engine ( again, big maybe).

My question is, what is it? What does it do? How important is it?
The hose is pretty ragged. If it has anything to do with the turbo system, it must not be functioning beacuse it actually has a rather large hole in it.
The car seems to run very well, so it is no worse for the wear.

Thanks in advance for any helpful responses.

Hoyt