Re: Where does this vac line go?
It is hard to tell from that video, but it does sound like a bearing of some kind going bad on one of your belt driven components, i.e. water pump, alternator, p/s pump, a/c compressor, etc. If there was smoke/steam coming from your hood, according to your friend, then I'd have to agree with GP and water pump would make the most sense based on the info provided.
Does the sound come from underneath the timing belt cover toward the middle of the engine? Have you checked your coolant level and is it low? If answers to both questions are yes, then it almost has to be water pump.