As soon as my car drops down to 'normal' idle after warming up, a heinous pshh-pshh-pshh-pshh-pshh noise starts coming from *somewhere*. This noise is constant (and 10x faster than you could do it with your mouth) and it sounds like a leak from somewhere, but everything is hooked up fine (I think)

My idle is fine, it's not like a normal vaccum leak. But like I said in the title, when I remove the hose from the bottom of the boost sensor, the 'pshh'ing goes away after about 1/2 a second and the motor purrs peacefully and quitely...

Is anyone familiar with anything like this?

 

Yes I also had my car make a real irratating sound but only at idle, is it kind of a high pitched sound?

 

ya, maybe more like a high intensity air psshh... It does it when I drive though, when I let off the gas. Could this be an exhaust leak? I'm thinking that perhaps my split air pipe could be loose? Since it's connected to all the emissions/vac crap, maybe it stops recieving air when I remove the boost sensor hose???

I guess I'll check it tomorrow, still any insight would be appreciated.

 

sounds like a tiny vac leak to me... then when you disconnect the hose it has a wider opening... See where i'm goin?
Lose the boost sensor and you also lose the turbo, so could be something to do with that thang too.

 

It's probably coming from the bac. If you had a stock filter on a normal RX-7, and remove the top black cover off the the filter, you can distinctly hear the bac pulsing. With the airfilter cover on, it's muffled. The bac cyles at approx 120hz. Remove the bac plug and see if the sound goes away or not.

If it does not go away, then my second thought is it's the airpump/acv/. Remove the airpump's belt and see it the sound goes away or not.

 

i dont think the airpump pulses that quick, I also think its the bac your hearing (dont know why your hearing it)

 

Actually this is a pretty cool post. Makes me want to go out and start the car and see if the bac is effected by removing the vac hose to the boost/pressure sensor.

 

interesting, I checked last night because a friend had been suggesting that it was maybe an exhaust leak. Anyways, it was definitely coming from under the hood right around the airpump/bac etc. I kind of assumed it was the airpump "pumping" air... But now that you mention the BAC, I don't know, I'll pull the plug and find out. But yeah, it's really annoying and loud especially while my car is warming up. It'll "blend in" as I start accelerating, but when I let off the gas, it pshh's like my car is farting. I'll try both of the 2 suggestions tomorrow and post my results, I don't want to live with it for much longer...

thanks dudezzz

 

Ok, I troubleshooted the problem today and found out that it was in fact my air-pump making all the noise... I left everything in place besides removing the belt and now my life is much better, lol.

Hailers: The only thing that happened when I removed the BAC plug was that the car's idle dropped a little bit.