Constant vacuum leak sound (Cause?)
 

Just a question but what really does cause our cars to make that constant vacuum leak sound. The sounds is worse when you remove the stock intake system.

Running on my INJEN Cold Air Intake I have had 6 guys roll up next to me to asking A) whats wrong with your Turbo? B) whats wrong with your engine C) man thats loud

What is the exact cause of that? the intake vac just that strong or what?

Cause for the first day i didnt notice it until i got home and pulled into the garage, man that Hiss is loud. In away it sounds kinda cool but then on the other side it really is a unnatural sound. And I dont have a blow off valve or sound to go along with it. lol which is a shame really.


Anyone?

the stock airbox really does a great job of muffling that noise. There is even a resonance chamber built into it which does nothing but silence the intake noise. Removing this makes it much louder. We don't mind it but some people do.

We took off half the CAI and eventually most of the rest and that hiss is excessively louder then my bud who has a CAI of the same brand.

Can anyone give me some background on anything related to the hissing sound and possibly EGR or IAC or anything having to do with the vaccum of the throttle body?

what it sounds like is a constant hiss at idle and at a constant RPM speed at any range of RPM.

I could be cruising at any speed and the hiss is very loud and constant.

I can interrupt that sound by stepping on the gas, anything that promotes accelleration , if i ease off of the gas the his comes back.

Before i drag it into Mazda dealership, i want to explore my options.

its a really loud loud hiss, i sound proofed the wheel well yesterday and it reduced the volume by about 40% but its still loud, people down the road turn their head,

I have about 150,000km on the car and i know i have popped in a PCV valve recently other then that , nothing else. but i have no performance issues, everything runs fine and like a dream.

Also the sound comes right out of the tip of what ever we disconnect, so if the CAI is fully intake its coming from the filter, you disconnect after the sensor , its coming from there.

Is there a vaccum pump thats on over drive or something? jesus. I have a 2001 Mazda ES my bud has a 2002 P5

could there be anything different between us?

Tough one. I would have to listen around it. Try spraying carb cleaner around the filter/seal. At each connection up to the manifold. When the hissing stops or the engine'stumbles - you found it.

Plug the PCV hose - did that help?

I would think persistance is better than bringing to a Mazda dealership and paying them $$ to do the same things i just listed...

kevante.redirectme.net/car/injen.mp3 Still no luck, PCV had no effect.


Are there any other valves or components that could possibly make this sound dealing with the intake manifold. i am positive its not the INJEN, because we took it off peice by peice and it was making the sound all the way up.

seems that my engine is generating it,

when i give it gas and accelerate the sound goes away, say 30% throttle and up, once i ease of the gas to coast or maintain speed. the hiss comes back, doesnt matter what speed i am at the his is constant and just as loud. it bounces off cars next to me and i can hear it.

There is no performance hit , at least from what i can tell, but it makes me a bit worried cause any kinda air leak sound cant be good if there really is air getting in or its that loud.

Question,

how does the vaccum system work. in proportion to throttle. what exactly is going on there, why would the sound go away when ipunch gas and accellerate. Vacuum pull right?

then when i let off the gas, does the car just let go of the pull, in a blow off sorta way?

doesn't vary in pitch or volume.