What the hell is that noise?

[StreetPizza]

It only occurs under about 2000-2100 rpm, when accelerating gently, usually in a fairly high gear. I\'m not sure if it\'s a \'breathy\' sound, or a \'scrapey\' one... it\'s kinda inbetween. It goes away completely after 2100 rpm, or if I let off the accelerator.

I\'m guessing it\'s something to do with the turbo system... at first I thought it might have been a loose pipe or something venting air, but if there was a problem with something like that, surely there would be other symptoms, but the car seems to run fine. (not that I have any point of reference though, since it\'s the only rx-7 I\'ve ever driven)
What I\'m worried about is that it may be something like excessive shaft play in the turbos, making the blades scrape. I really don\'t have the money right now to get the turbos rebuilt/replaced. The car only has 37k on the clock, would have thought that was too early for problems like that to crop up?

Any suggestions?

Cheers.

[Dr Gonzo]

Mine does a similar thing at those revs although I can\'t confirm whether it\'s the same noise! After much scratching of head and poking around it turned out to be the air filter (bloomin\' great thing) vibrating against the engine bay...

[amp]

check your air pump..

[Fenix2k]

What year is your Rx? Was checking newera\'s site (as i regularly do) and they had this info on a couple of Rx\'s they had in stock:

"The Air Pump has noisy bearings and the electrical plug for the magnetic clutch has been disconnected. Air Pump bearing failure is common on older RX-7\'s and isn\'t detrimental to performance (If anything it allows the car to produce more power more efficiently at the expense of emissions). With the induction kit fitted, if connected - an air pump would make strange sounds as it came on, which is primarily why these are often disconnected on RX-7\'s."

So this may be your problem??

[StreetPizza]

Ah, that could well be it. Mine\'s a \'92, so that\'s a distinct possibility. So I guess the plan is to disconnect the air pump, and see if it still makes the noise. Cheers guys. I\'ll give that a shot.