Turbocharger Problem? Knowledge Needed.

[Tiger_kpt]

Right... literally less than 24-hours ago I got my car back from WGT\'s after over £3000 on parts and labour.

See the following link for full spec -
http://www.mazdarotaryclub.com/forums/showthread.php?t=37511


Done a fair few miles in it since, all seemed fine. Until we stopped for some food and drink and left the car for 30-minutes or so.

Got back in and started her up.

Immediately a weird noise began. Best way to describe it is as a low pitched humming or farting noise! Imao. I know this about it: -

a) It is coming from around the area where the turbochargers are.

b) It only occurs at idle up to (and I mean on the dot) 2500rpm. At or over 2500rpm the noise disappears and the car is fine again. Below this the noise comes back at 2500rpm on the dot and below again.

It may just be me but she seems a little more juddery on the transmission also (could just be me though). Could this be a mount of some kind?

I\'m just wondering if any of you guys know of similar symptoms and could give advise. I\'m thinking it is turbocharger or exhaust side of engine related.

A few things that bothered me when the car came from Pip\'s, which may be or may not be anything. But I had the Greddy dump valve fitted on the Greddy elbow on a flange. Pip left the two standard dump valves on. So they are still at this side of the engine.

Also... cat was removed and Greddy pullies fitted. But instead of removing the airpump, he used the pullies with a longer belt and left the airpump active in the absence of the cat. I know that people complain about a "moo-ing" sound from the airpump coming from aftermarket filters. But this sound isn\'t that. It isn\'t coming from filters, coming from turbo area of engine bay. And occurs between idle (750rpm and 2500rpm), so this tells me it shouldn\'t be that. Also... as a test removed the airpump pipe from the airbox, sound still occurs.

So... any ideas guys? Am at my witts end after spending so much money on her and having less than a days pleasure out of her! Lol.

Cheers.

[Tim_B]

Sorry to hear that

Met you in WGT yesterday so thought I\'d say Hi.  Dunno what the noise is, I\'d give Pip a ring tomorrow (though I guess you\'d thought of that :o )

Your from Long Eaton - thats where I bought my Rex :driving

[bobert]

Have you tried unplugging the air pump to see if it stops?
When I was on twins my air pump used to make humming noise around idle.
Apart from that I bet your well chuffed with your car:3gears-lh

[FD600BHP]

Right... literally less than 24-hours ago I got my car back from WGT\'s after over £3000 on parts and labour.
 
See the following link for full spec -
http://www.mazdarotaryclub.com/forums/showthread.php?t=37511
 
Immediately a weird noise began. Best way to describe it is as a low pitched humming or farting noise!. I know that people complain about a "moo-ing" sound from the airpump coming from aftermarket filters.
 
hmmm,check for small cow with wind trapped somewhere.:WaveBye

[Tiger_kpt]

Yeah this definitely isn\'t a low humming noise. It\'s a rather loud aggressive noise. Sounds like air escaping under pressure in time with the rotors revolving. Not metallic or clunky though if you get me and definitely from the turbocharger area of the bay. Seems ALOT hotter under the engine bay also.

[Tiger_kpt]

Hi Tim / Bobert. Yeah from Long Eaton. Only been here for 9months though. Yeah chuffed with the car, but this at the moment has taken the icing off of the cake. Apart from this though she goes like stink. Paranoia has set in. Never had this until I owned an RX7. Imao.

[Tiger_kpt]

Well... sending a big thanks out to you guys yet again! Went to my car this morning, unplugged the airpump and no more drowing dog noises! Sweet as a nut. Thanks all. Worrying over and can now enjoy for the time being.

[bobert]

I told you it was the air pump:D

great figures from wgt

Whats next on the list for your rex?
more power I say:mmmm

[Tiger_kpt]

Not sure to be honest. The car is my daily driver and I think more power would be unecessary. Seems ALOT faster than it was before. Already nearly caught me ut today twice! So quite happy with power for... now. lol.
 
I think the next steps would be Brembo cross drilled and grooved brake discs all round with some decent dust free pads.
And some coilovers on the suspension.
 
What suspension coilovers and brake pads would you guys recommend.
Also in terms of my dyno results... what do you guys think to them when compared to the spec of the powertrain now? A bit low? Or about right? Pip said that the results were better than he would have expected them to be by an extra 10+bhp. Hmmm???