Don't know if anyone else gets this with there 2.2 petrol (Z22SE engine), although a bit difficult to describe, but basically e.g in 3rd or 4th gear and say under 2,000 rpm and just on slight throttle I can hear this strange noise , like a sort whirring sound , but not what I would say is anything like a bearing sound but more like induction / exhaust type of thing, if I accelerate or keep the revs up over 2,000 rpm it disappears; baring in mind the exhaust is fine and no holes, only thing I can think of is that it might be down to the airbox mod' and putting the longer air intake back on (had put the shorter one on yonks ago, but refiited longer one some few months back) , I knew I shouldn't have had my ears surringed a while back as I'm starting to hear allsorts of strange noises with this damn car!!LOL
Cheers Pete