Hi guys... I am new to this forum, so I would firstly like to say hi - and apologise in advance if I have posted this query in the wrong forum etc.... (if so, maybe someone could point me in the right direction)
I have a 1999 MK4 Golf GTi TurboÂ…. The turbo has always made a nice / quiet whistling noise when you boot it, but more recently I have noticed that the whistle is starting to sound a bit rough!
It is hard for me to describe the noise in words, although it is the same noise but “broken†with a little interference / stagger breaking the seamless flowing whistle (if that makes any sense?

)
I have not noticed any (noticeable) difference in performance – just the noise.
Does anyone know what this could be? Is the turbo on its way out?
Cheers,
Jon.