Help ID this possible problem

[uss2defiant]

I noticed a hissing-like sound when I stepped on the throttle.

Here's a vid of that sound.
Is this normal or a potential problem?
It sounded like it originates from the back some where, I couldn't pin point the problem.

Thanks.

[YT]9OAyb27_wVY[/YT]

 

[LibertyTC]

IDK never really noticed this hissing situation.
The intake, at front of air box, can make a hissing sound as the air rushes in.
Throw a towel over top of the intake,without completely blocking it, and see if the sound is still present?
It does sound more like the back though.

 

[CzarKJ]

My throttle body makes a hiss when revved. I always thought it was just air going past the plate making that noise.

 

[uss2defiant]

ah okay. On a few occasions I hear that hissing sound on the left by the air box.
This is good news then that it is not an abnormal sound.

Thanks guys!

 

[dude1116]

Sounds normal to me!

 

[uss2defiant]

Great! I was afraid it might have been a crack some where.
Thanks.

 

[John3seventeen]

Sounds like a vaccumn leak - and your breather hose on the right is kinked almost shut.

 

[uss2defiant]

bah...
my thought were a crack or a vacuum leak some where.
I'll have to look around.

What's the best way to check for vacuum leaks? use a spray bottle w/ water and hear whether the engine sounds different?

That breather hose connects to the PCV. I'll take a look at it again. It could be the angle and lighting making it look like it is kinked.

 

[dude1116]

:shrug: Mine's done that as long as I can remember.

 

[TwoBobsKJ]

Yea, each time you open the throttle like that the vacuum in the engine pulls air past the butterfly in the throttle body creating the hissing sound. Perfectly normal :waytogo:

Bob

 

[uss2defiant]

great!
I'll still do some sniffing around.

Does anyone know what vacuum lines are back there?

 

[John3seventeen]

If someone else doesn't answer I'll try to get you a pic from the service manual tomorrow.

 

[uss2defiant]

If someone else doesn't answer I'll try to get you a pic from the service manual tomorrow.

Hey no worries. I have the FSM as well.
Just thought to ask if anyone know what vacuum lines are back there on top of their head to save me some time searching the FSM.

 

[twowings]

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It may not be wise to ignore hissing coming from under the hood....