Just thought id add this in case it saves someone a bit of time.
Car was going great then just started driving like a non turbo sdi.......no oomph!
It felt like the turbo just wasnt working at all.
No dash lights or faults showing and no funny noises.
Traced the problem to a small vaccuum pipe which runs along the plastic air pipe
at the rear of the engine which had come off.The pipe is hard to see as its surrounded
by several other vaccuum pipes and clipped on to the air pipe.I had removed the top engine cover and started the engine to have a listen and you could hear the sucking noise from rear of engine.you have unclip the pipes to find which one is off.
Connected pipe back up and secured with a small cable tie and hey presto
good as new.hope this helps.
