I don't think that "woo" noise any indication of anything - most turbo cars do it, but is often unheard/silenced due to the induction/exhaust system design and sound insulation, some with inferior induction silencing will make a moan under light load. The key is how loud it is.
A faint "woo" noise off-boost just off idle (under light load at 800-1200rpm, like when pulling way gently) is pefectly normal and just the nature of a turbo as it starts to spin up to speed but not producting any boost pressure. However If it made the noise whilst on boost at higher revs, or it was very loud. then thats a bad thing, and would be a cause for concern. High speed noises under heavy load/high boost are indicative of leaks or chipped blades.
FYI a 140ps TDi wiith the PD fueling/head will be code BKD or BKP. But the common rail will be code CBxx or CAxx where "x" is alternate letter depending on spec. Different engine - fitted depending on model year (old cars = PD, newer ones = CR).
The PD version does use a little oil - so keep it checked and topped up between services and DO NOT overfill it (too much will kill it), and its vital to use VAG 505.01, 506.01 or 507.00 rated oil.
Last edited by ALi-B; 15 November 2010 at 03:44 PM.