Hi guys,been driving through Europe on a roadtrip with other half in our A4 B6 2,5 tdi quattro for the last few days now with great success and total pleasure leaving behing almost everyone on the large motorways of Italy,Austria etc but since yesterday and after stopping by the Netherlands a serious peoblems seems to have appeared. On acceleration on 4th gear especially and as the rpm goes up at around 2000-2500rpm a METALLIC noise comes from the front of the car and it reduces/goes away over 2500rpm. No power loss seems to have appeared but BLUE SMOKE comes out the back at cold and not so easy start. Been ckecking oil level and it has dropped just a tiny bit for the last 1000K. Car has had a large service with timing belt/belts and other bits and pieces just 3weeks ago before we hit the motorways! I'm afraid it might be a TURBO ISSUE??? ANY ADVICE would be greatly appreciated especially here,a couple of thousand miles away from my favourite mechanic back home!!