At 180K miles I'd be amazed if it was still on its first turbo - I don't know anyone (myself included) running a car with the 1.9 diesel that has got a turbo to last beyond 100K. My turbo blew somewhere around 80K but that's on a 130bhp engine so maybe they use a different turbo on the lower powered 1.9s?
(My previous car was a Peugeot 306 turbo diesel - I sold that at 180K miles and that didn't have anything done to it beyond routine servicing
)