The turbo on my MY95 WRX seems to have got louder over the last few thousand miles. The car has now done approx 60k miles (20k in the last 12 months).

The 'whistle' noise is now more pronounced over about 4000 revs. It may be paranoia, maybe I don't have the streo as loud these days (!), but I like to have peace of mind.

Do turbos need 're-conditioning' or similar after a certain amount of miles?

 

If you're not getting smoke out of the exhaust (after a run when it's all nice & hot, let it idle for a minute then rev it at idle. If no smoke, good; if white / blue smoke, seals are worn) then it should still be OK. Might be worth going over the plumbing and tubing to make sure everything's snug with no leaks / cracks but if you don't find anything, and it's not smoking, it should be fine.