MK5 rattle near tensioner - Failed Alternator pulley?

[epidemic]

I would have it checked out by a VW shop, that could become expensive.
Did they also do the water pump?
Our BKD went 200k before needing a water pump last month, but it could be a years of service thing as we are now over ten years.
Also in the BKD there's a harmonic balancer. If that fails, which is rare but happened to us when the water pump leaked coolant onto the HB causing the rubber to denature, the serpentine belt will go loose and you may get those noises.

Hey mate I managed to swap out the alternator pulley today. Difference was night and day. I actually took my car to a mechanic this morning after yesterday failing to get the alternator pulley off myself. When I took the car in I could reproduce the noise and the tensioner was rattling everywhere. He even mentioned it as not being a problem.. plus they wanted to charge $220 to replace the pulley! Cya!!!! Terrible advice too.

I read up some more and tried again tonight and replaced it myself. I needed to use vacuum metal pipe as a breaker bar to crack the bolt!!

Anyway fixed the issue right away with the new pulley!! Noise gone now just pure TDI racket!

Also RE the water pump - that will be getting replaced with the timing belt when I do timing belt which will be soonish for peace of mind.