Question: Venting boost?
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Question: Venting boost?
At higher RPMs under boost I hear a rush of air under the hood briefly, followed by a *really* loud whooshing sound. Doesn't seem right - am I venting boost? Is there a way to check without tearing apart the Y-pipe and crossover tube?
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If it only happens when you shift, it's your blow off valve releasing the boost. That's supposed to happen. (based on the noise, you probably have an atmospheric BOV). The BOV will also engage when you rev and engage boost and then go back to idle... basically any time the turbos have shoved more air in than the engine needs or can handle.
A boost gauge would tell you if you are venting boost unnecessarily.
john
A boost gauge would tell you if you are venting boost unnecessarily.
john
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I've got a boost gauge - boost doesn't decrease when this happens, but it never climbs past a certain threshold.
If there is a leak somewhere, the piping is only able to handle up to a certain psi before the crack is forced open and the extra pressure is vented, right? If there was really a leak would boost spike and then *decrease* as the crack is opened? That's not what I'm seeing.
It doesn't happen when shifting, it's happening under acceleration. The pedal is down, the boost is at a constant level but the "whoosing" sound grows increasingly louder.
If there is a leak somewhere, the piping is only able to handle up to a certain psi before the crack is forced open and the extra pressure is vented, right? If there was really a leak would boost spike and then *decrease* as the crack is opened? That's not what I'm seeing.
It doesn't happen when shifting, it's happening under acceleration. The pedal is down, the boost is at a constant level but the "whoosing" sound grows increasingly louder.
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Originally posted by sabreWulf
I've got a boost gauge - boost doesn't decrease when this happens, but it never climbs past a certain threshold.
If there is a leak somewhere, the piping is only able to handle up to a certain psi before the crack is forced open and the extra pressure is vented, right? If there was really a leak would boost spike and then *decrease* as the crack is opened? That's not what I'm seeing.
It doesn't happen when shifting, it's happening under acceleration. The pedal is down, the boost is at a constant level but the "whoosing" sound grows increasingly louder.
I've got a boost gauge - boost doesn't decrease when this happens, but it never climbs past a certain threshold.
If there is a leak somewhere, the piping is only able to handle up to a certain psi before the crack is forced open and the extra pressure is vented, right? If there was really a leak would boost spike and then *decrease* as the crack is opened? That's not what I'm seeing.
It doesn't happen when shifting, it's happening under acceleration. The pedal is down, the boost is at a constant level but the "whoosing" sound grows increasingly louder.
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Originally posted by areXseven
Is your Fd an Auto or Manual Tranny? As the "venting sound" is occuring, does it diminish or completely stop when you accelerate?
Is your Fd an Auto or Manual Tranny? As the "venting sound" is occuring, does it diminish or completely stop when you accelerate?
Originally posted by Seldon
you might have a BOV releasing prematurely
you might have a BOV releasing prematurely
Originally posted by RX7SpiritR
how much boost your getting?
how much boost your getting?
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Originally posted by sabreWulf
Oh sorry. At best I'm getting 7 psi
Oh sorry. At best I'm getting 7 psi
If you check all your couplers and remount them and you still have boost problems, come back and we'll go from there.
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Sounds like a cracked IC coupling/pipe or Y-pipe coupling....or cracked cross-over tube. Or bad BOV. Check these parts very carefully.
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It sounds like you just have a plain boost leak somewhere if your only getting 7 psi. Check all the couplers, and pipes.
Last edited by RX7SpiritR; 10-03-03 at 03:14 PM.
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