Sheepsplitter

My cars done 60K miles now, and the last 5K have been with a slightly noisier turbo [WRX STI4].
I'm going to have the turbo taken off, inspected and rebalanced next week.
What sort of cost should I be looking at for this service (assuming it needs rebalancing, which I'm pretty sure it must).
Anything else I should get them to do whilst it's off ?
Any advise would be much appreciated.
Thanks

James_PowerMad

Sorry, can't answer your questions, but I am interested...

What is the noise like? Is it a high pitch whining noise? If so, then how loud is it?

My MY98 (50k) has produced a noticable whining/whistling when under load since I first got it (at 40k). I assumed that this was normal for any turbo, but now I am wondering how much noise is 'normal' for a healthy turbo?

BTW, the whining is not the BOV, cos' I just got a new Forge one (still same whine).

Does everyone experience whining in their Scoob??

Sheepsplitter

The noise is apparent even on starting the engine.
It's definately the turbo.
Also when you switch the engine off you can hear it 'spin down'.
It's just like a small electric motor sound, but not to be confused with the sound it makes when on full boost (I'm used to that, and it's not possible to hear it unless you are doing >3000rpm).
Your description of a high pitched wine sounds about right.
It's about as loud as the fan units, but obviously it comes from the turbo side of the car :-)
The sound started quite some time ago, and I sort of put up with it, but I'm just a bit afraid if the turbo goes pop it might take some/all of the engine with it and make things very expensive indeed.
I know for certain that the majority of Subarus (STI or normal) do not have this sound.

BTW It has nothing to do with the airbox changes I've made, as it was not doing it until 2 years after the mods, just in case anyone is thinking it's since I fitted a more open air filter config.

I don't think there should be any turbo noise until it kicks in at 2500-3500rpm (depending on model and mods done). Certainly I don't expect it to make the noise when stood still on the drive ticking over.

James_PowerMad

Thanks. I have heard that when turbo bearings get worn, the compressor blades can start to chip away bits of metal from the turbo casing, and the bits aint to healthy for the piston liners.

Do you know if your turbo is blowing much oil into your engine?

Sheepsplitter

Don't know if it's blowing oil in.
Is there an easy way of finding out ?

One thing I've noticed is that it seems like it gets quieter as the oil heats up, and also on cold days it doesn't seem quite so loud (once warmed up) - could be my imagination of course :-)