- or at least, so it seems.

More smoke than usual ("eau de Mobil 1")
Boost comes on later than normal
Power sometimes dies off at around 5000rpm

And there is a somewhat intermittant "quality" to it, sometimes it boosts almost okay, sometimes not.

My theory is that a day on the track yesterday finally did it.... car is from 1992 and has 140.000km on it, so it seems only logical that the turbo should give up just about now. I canīt really say that I am surprised :-/

How can I confirm for sure that itīs the turbo?