My friend's VW Golf 1.9 TDI makes a hizzing noise when he rev's hard, does this mean is turbo is going or it's gone??.

My OEM turbo at 1.5 bar made far more noise than my TD stage 2 at 1.8 bar...

Think its how hard you're pushing them - actually like the noise tbh....

I think they just go 'pop' and then nothing when they fail. Dunno for sure - you'll have to ask someone who's blown a turbo :-)

If it's a hissing noise,you probably have a leak in the boost pipes somewhere, check them, my fabia vrs was doing this and it was the pipe not fitting correctly.

Checked it out, and now it's ok?

My turbo whistles when its working, no sign of a hissing noise.

Ben

Is this expensive to repair?.

Is this expensive to repair?.

Sometimes the pipes can split and I would think they would be anywhere from say 15 quid upwards, but check the connections, there could be a loose one.

If there is an intercooler there could be a hole in this which is not uncommon but it's a bumper off job to really check this out so try the connections etc first.

Hope this helps,

Ben

Thanks.