yes this is another question in concerned to my hissing throttle body.. checked for air leaks - none that was found fixed teh idle screw problem no it idles like a charm

just when i uually hit around 3k rpm i start to hear a hissing.. put if i floor it i dont hear it at all..

only when the peddle is depreesd at normal acceleration.. from around 3k - 4 k it hisses throughtet 1 - 5th gear..

and this is driving me insane any help appreciated

 

It could just be the sound of the air passing around the throttle butterfly.

If you think you might have a leak, at idle try to spray WD40 around the tb, and all the rubber hose connections. If you hear a sucking or bubbling sound, you have a leak. If the idle goes up or down, you have a leak.

 

i tried the wd 40 and didnt seem to have any leaks i will replace teh tb gasket from the plastic stock one to a 96 elantra paper one..

the sound is like a fan belt type of hissing more like asqueeling but its coming from the tb. and the gas peddle.

if it is the the butterfly in the tb and teh air passing it is their any alternative to prevent this from happening this is the old sr 60 mm tb. that i have.

 

Just wondering, does it hiss at certian RPM levels or certian Throttle position levels?

Does it happen at 3000 RPM regardless of throttle position? If you wind the engine to 6000 rpm, then just let the engine slow down naturally, does the sound go away when you take your foot off the gas, or only after the RPMS drop below 3000.

 

well if i go to say 6000 rpm and let my foot off the gas it does not come back on with my foot of the gas pedal.

only at around 300k and pressing the gas peddle slightly it does this

if i floor it from say 2k up it will not hiss at the 3k mark..


this hissing only occurs from 3k to about 4k not below not after just that range and only when gas pedal is slightly pushed in.

 

You say squeling? Or hissing? Is it air sound going through a narrow place or is it a squeal? Are you positive it comes from the throttle body? Last question are you Naturally aspirated or Turboed? Regards

 

its like a very loud squeel i guess i refer to it as a hissing and i am positive it is coming from the tb.. it kinda sounds like a loose fan belt with a .lil bit of blow off valve..

i am n/a , not turbo or supercharged

 

If it only happens at partial throttle, then it is probably air sucking around your TB butterfly.

I'm guessing the reason you notice it at 3000 rpm is that the engine is not loud enough to cover the sucking noise.

You can't really hear it at 6000 rpm because #1, the engine is so loud by then, and #2, you really can't do 6000 rpm with only partial throttle....

 

The hiss of an intake leak under vacum is mainly at low rpm (sucking hiss) since the vacum is dramatically reduced at the intake manifold at higher rpm under acceleration. You get any noise in deceleration like go to 5000 and then take your foot off all the way and let it go down to 1000 say in 2 an 3 gear? Are you sure is not coming from a belt or the transmission?

 

when teh car decellerates the hiss does not occur only when in gear 1 2 3 4 5 i get this noise

if im in nuetral i do not get the squeel/hiss sound

hmmmm