"Sharp edges" possible issue on intake after 62mm throttle body upgrade causing whistle?

[aidanm]

Recently, I installed the BBK 62mm throttle body on my 2002 Jeep TJ Sahara and whenever I slightly have my foot on the accelerator, it has a whistle that sounds almost like a turbo and whenever I let off the accelerator or increase the pressure on the gas pedal it goes away. I've heard this could be from sharp edges? What and where exactly are these "sharp edges"? I heard turning the Idle set screw could fix this because I didn't change mine at all just installed it. I enjoy the sound because it sounds like a turbo, but it does get annoying after a while on top of a much louder whistle that I believe is coming from a vacuum leak somewhere in the engine just can't tell exactly from where. (Any help with this too would be greatly appreciated). I've heard it could be a loose intake manifold or just a vacuum leak. Only happens when it's colder outside and once the Jeep warms up it goes away. Happens whenever I let off the throttle. Thanks!

 

[C.J. Roberts]

I hope that you didn't "upgrade" your throttle body thinking that it would gain you anything. Because it won't. The factory TB can take in more air that the engine can use. Put the factory TB back on and see if your problem goes away.

 

[aidanm]

I actually gained some pretty good acceleration and throttle response from it.

 

[TJ Jim]

I had a whistle like that. Tea kettle was the description and cool weather affected it the most. Also touch the throttle and it would go away. Mine was the intake/exhaust gasket.
Like @C.J. Roberts said above, does it do it with the oem throttle body?
There is no idle adjust screw the computer controls idle through the idle air control. (IAC)

 

[aidanm]

I had a whistle like that. Tea kettle was the description and cool weather affected it the most. Also touch the throttle and it would go away. Mine was the intake/exhaust gasket.
Like @C.J. Roberts said above, does it do it with the oem throttle body?
There is no idle adjust screw the computer controls idle through the idle air control. (IAC)

No it didn’t do it with the stock throttle body

 

[aidanm]

The sound that I believed was a vacuum leak did sound like a tea kettle and that was happening before I put the throttle body on, started as soon as it started getting cold. The other whistling sound started after I put the throttle body on and happens only when your foot is just slightly on the gas.

 

[TJ Jim]

So you probably have two leaks. One vacuum and your new throttle body. If you can recreate the throttle body whistle with the hood open and moving the throttle body butterfly valve by hand, maybe the shaft holding the butterfly is bypassing air?
Is this a new or used body?

 

[aidanm]

So you probably have two leaks. One vacuum and your new throttle body. If you can recreate the throttle body whistle with the hood open and moving the throttle body butterfly valve by hand, maybe the shaft holding the butterfly is bypassing air?
Is this a new or used body?

A new one

 

[MikekiM]

I actually gained some pretty good acceleration and throttle response from it.

 

[clay county tj]

Do you happen to have a cold air intake? I have a '06 that had a Banks cold air intake and Banks exhaust with a larger throttle body and an Edge module when I bought it. It makes a lot of similar noise. I believe most of the noise is coming from air cleaner.
Runs good though so I don't really worry about it.

 

[aidanm]

Do you happen to have a cold air intake? I have a '06 that had a Banks cold air intake and Banks exhaust with a larger throttle body and an Edge module when I bought it. It makes a lot of similar noise. I believe most of the noise is coming from air cleaner.
Runs good though so I don't really worry about it.

No I don’t have a cold air intake but am getting one soon, just got the banks exhaust and installing it this weekend

 

[Jerry Bransford]

I actually gained some pretty good acceleration and throttle response from it.

No you didn't, that's simply the placebo effect hard at work. As C.J.Roberts indicated, the OE throttle body is well known to have a big enough opening to easily allow far more air in through it than the engine can consume/ask for even at redline rpms at wide-open throttle. Really. I actually installed a 62mm throttle body well over 20 years ago into my TJ thinking it'd help but I detected no difference. Then Jeep's chief engineer (James Repp, the "father of the Jeep Rubicon") I talked to on the phone several times on a different subject told me about how the TJ's OE air intake system was specifically designed to have absolutely no restrictions anywhere.

 

[Jezza]

No you didn't, that's simply the placebo effect hard at work. As C.J.Roberts indicated, the OE throttle body is well known to have a big enough opening to easily allow far more air in through it than the engine can consume/ask for even at redline rpms at wide-open throttle. Really. I actually installed a 62mm throttle body well over 20 years ago into my TJ thinking it'd help but I detected no difference. Then Jeep's chief engineer (James Repp, the "father of the Jeep Rubicon") I talked to on the phone several times on a different subject told me about how the TJ's OE air intake system was specifically designed to have absolutely no restrictions anywhere.

Yet, actual dyno numbers have proven otherwise.

 

[aidanm]

No you didn't, that's simply the placebo effect hard at work. As C.J.Roberts indicated, the OE throttle body is well known to have a big enough opening to easily allow far more air in through it than the engine can consume/ask for even at redline rpms at wide-open throttle. Really. I actually installed a 62mm throttle body well over 20 years ago into my TJ thinking it'd help but I detected no difference. Then Jeep's chief engineer (James Repp, the "father of the Jeep Rubicon") I talked to on the phone several times on a different subject told me about how the TJ's OE air intake system was specifically designed to have absolutely no restrictions anywhere.

The throttle does feel stiffer as well so that could lead to the feeling of better acceleration and throttle response, it at least feels better to me even if that’s not what the facts say.

 

[Jezza]

FWIW my S2000 made the same noises when you had the throttle around 20% or so. The air hits the throttle body just right and makes a whistle sound.

 

[aidanm]

FWIW my S2000 made the same noises when you had the throttle around 20% or so. The air hits the throttle body just right and makes a whistle sound.

Were you able to ever fix it?

 

[Jezza]

Were you able to ever fix it?

No, they do it stock. the factory fixes it by using a baffled airbox with chambers to muffle the sound. You could try to "soften" the sharp edges, but don't go too crazy and change the fit between the blade and the bore.

 

[aidanm]

No, they do it stock. the factory fixes it by using a baffled airbox with chambers to muffle the sound. You could try to "soften" the sharp edges, but don't go too crazy and change the fit between the blade and the bore.

What are the sharp edges?

 

[SPECWAR]

What are the sharp edges?

You better leave it alone.

 

[BC Moto]

I have a aftermarket TB also and when I have the air intake on it, that thing would make the whistle sound due to the air coming through the filter. The stock airbox is on it now with less whistle. I was in the aftermarket world for many years and ive heard the same thing when people say it doesnt do any good only harm. I have proven with dyno sheets and other facts in the past so I dont bother to argue with people who think otherwise. The bigger TB does have and effect on throttle response and I agree that it made a difference.