ELP CAI Question...

[MFCC08]

Hey guys,

So I recently bought the legendary ELP CAI, and threw it on my prizm, but now I have a question for you all.

There seems to be a humming coming from around the throttle body area. It is a deep, low tone, and only appears at idle. Does anyone know what this could be?

BTW...the car now PULLS!!!

[burnout8488]

Originally Posted by MFCC08

BTW...the car now PULLS!!!

Is there really that much of a noticeable difference? :O

The noise could be normal, but something that was eliminated by the quiet factory airbox. I would expect a loud hissing, but can you describe the hum a little better?

[MFCC08]

Yeah there is a pretty big difference honestly. When you rev the engine, it revs up a lot faster. There is a noticeable difference from idle to 4k. The car has gotten faster especially from going 30 to 60mph, and then 60+mph is A LOT faster. The gearing feels a bit different though... It seems to shift itself at 30 for first, instead of 32 or 34. Don't know... I had to wedge some foam in the resonator hole to keep the pipe from rattling, and between the fuse box and the pipe too.

The humming noise is a really low tone, and consistent. I used to play trombone, and I would guess the sound is like a low G or F in bass clef. It is coming from around the intake manifold and the throttle body area. It is really loud, almost matching the sound output from the engine. I drove it this morning and it wasn't there. I looked some info on it last night, and i got an "idle air control valve," that might have to be cleaned... hopefully that helps explain it a bit better. Oh, and it was present driving and in park.

[fishexpo101]

I'd give the throttle body a good cleaning, just tossed on a new intake, might as make sure that it has something clean to run to.

If the vibration seem to be keyed to engine speed, likely it is a resonance issue. Try and shift the resonant frequency by adding more padding or even putting a piece of sound deadening material on the intake tubing. Some have found running a different filter assembly or angling the filter can help with the "droning" noise as well.

Running an aftermarket intake generally has more noise associated with it - nothing wrong with operation, just the nature of the modification.

Could also be something not directly related to the intake - could be a leaking exhaust donut. Pretty common on this generation. May not have noticed it with the OEM intake, but the ELP might make it stand out more.

[Bdub215]

Originally Posted by burnout8488

Is there really that much of a noticeable difference? :O

The noise could be normal, but something that was eliminated by the quiet factory airbox. I would expect a loud hissing, but can you describe the hum a little better?

both of my setups intake setupsdidn't hiss. the filter just had a dull hum to it. so im gonna say its normal.

[Bdub215]

Originally Posted by MFCC08

Hey guys,

So I recently bought the legendary ELP CAI, and threw it on my prizm, but now I have a question for you all.

There seems to be a humming coming from around the throttle body area. It is a deep, low tone, and only appears at idle. Does anyone know what this could be?

BTW...the car now PULLS!!!

i wanna bump this thread to show the OP this vid.

You Tube

You Tube

[MFCC08]

First of all thank you guys for all the responses! I'm writing a paper as we speak, and my schooling has been ridiculous lately, but thank you!

SO, I checked out the exhaust donut, and it probably is that. Thanks Fish for replying so quickly!!! You are the Corolla Man! I also read that on really cold days, the sound can appear. It was like 20 degrees the day it happened. Just have to live with it...

BDub...beast setup man! Like the IM/TB! Sounds nice! I bet just the IM/TB saw a significant increase in output? I have to get a vid and pic up for you and Burnout! I am on thanksgiving break tomorrow!!!! So i will get that up!!