Hi i have a 2000 1.9tdi with 120k. I have a noise, always been there, if im stationary and rev it a little , as i take my  foot off the throttle there is a noise, just for a second or 2 like i duno a metalik sort of sound like something needs oiling , ive put 12.000 miles on it and its always been  there, but more noticable in the last few days. the turbo works fin apart from the occasional overboost prob.  just had new alternator tensioner and belt last week, and think garage would have said if there was a prob,, any ideas guys..   Bin an expensive 18 months new rack, new front spring new rear spring new fusebox on battery new window regulator ( I did that lol ) and this week 2 new lower suspension arms and alternator tensioner and belt.. :( so hope this isnt anything serious ) ... 

 

I'm afraid is a bad flywheel