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Discussion Starter · #1 · (Edited)
So I recently installed an Injen intake about a week ago and didn't notice the hissing which seems to be coming from the air filter until a few days ago. Is this normal? If you close the hood and stand outside the car you can hear it, it's not extremely loud, but noticeable. It kinda sounds like the air coming out a ball if there was a whole poked in it or something. Can anyone help me figure out what the problem is? or if it's normal... the air filter was cleaned about two months ago if this makes any difference.. thanks!

edit: oh, and this isn't under driving conditions or whatever, you can hear it at idle, too. I can't hear it from inside the car while driving because of the exhaust, but i'm sure it's still hissing away at that time, too..
 

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don't worry, this is normal. the hissing is the engine sucking in air. remember that unless your boosting with a turbo/supercharger setup, your intake will always be under vacuum. the hissing sound your hearing is the air being pulled through the filter.

i have a vented carbon fiber hood and i can always hear the intake if my windows are down... even more so right when i floor it. for a split second before the exhaust note hits it sounds like the engine is taking a huge gulp of air.
 
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you can also check to see if the clamps are on tight. i know sometimes there could be a small gap that may cause some hissing.

thanks,

Jeff
 

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Discussion Starter · #4 ·
I see, thanks everyone!

and @BlagPerl, it should still hiss even at idle?
 

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completely normal with any N/A car with an open element filter.

Notice when you pulled off the stock piping the little resevoir underneath the pipe? Yeah that muffles the hissing and makes the intake quieter. Aftermarket intakes do not have this, thus the hissing and the louder WOT sound.
 

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Discussion Starter · #7 ·
mm, cool. thanks everyone!
 

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idle hissing in fine... that's when i notice mine more because the engine/exhaust isn't as loud.
 
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