I tried poutting this in general without any replies, hopefully I'll have more luck here...
My MY95WRX has been making an odd noise on boost recently, kind of like a whistling - the best way to describe it is like a quiet electric drill spinning up as the boost builds. It starts at 2800rpm, builds in pitch until 3500rpm (or thereabouts) and then stays at a constant pitch until redline.
It's not overly loud, but the noise was definately not there before. No impact on performance.
I have had the intercooler and pipework off to search for a leak in the intake tract after the turbo, and can't find one (although I haven't pressure tested the IC).
So, with my (very) limited knowledge I figure that the bearings are close to fried on the turbo? If that's the case, what will happen when it fails? Are we talking fins hit housing, filling the engine with bits of metal (I don't like the idea of that scenario.....).
Please, please, please. Any input is appreciated. I really don't want to be taking the turbo off if it's not absolutely necessary. And if I do, will one of the TD05 rebuild kits do the job?
Thanks guys (and gals).

 

The turbo on mine was a little noisy too, but the noise did disappear after i rebuilt it. But do wait for more advice on here. The bearings will have to be reallyy badly worn for the fins to start touching the compressor housing. So to summarise if its only a quiet noise theres no major panic. Could it be the BOV or just a bad joint?

The downpipe from the turbo is a pain to remove, but if you know what you're doing with a turbo you can actually remove the compressor housing and bearing assembly alone, this will mean >>> you could leave the turbine housing connected to the down pipe, trust me this is the simplest route if the nuts on your down pipe are bad. (99% of the time the're a pain).

Good Luck

Baly

 

Thanks. That's a real help.
The nuts on the housing are all ok (I had the turbo off earlier in the year when the engine was out). Yeah, I guess that a leaky BOV could also be the culprit, I'm on the standard one so it could be tired.
I'm thinking of getting a sports cat in the DP, so that may be the opportunity to inspect how freely the compressor turns - but appart from understanding the basic mechanics of a turbocharger, they are a new thing for me.