question for L99 guys..

[bigssc]

installed my cold air inductions intake and i love it but heres my question, when im at slow speeds and than i step on a little bit so i can go a little faster i hear a noise ive never heard before, its almost like a "swoosh thud" if that makes any sense what so ever lol its hard to describe. it doesnt sound serious at all but my old K&N intake i never heard this sound. i also dont have my car tuned yet and my other mods in my sig havent been installed yet. so im thinking because i went from a plastic k&n to a metal CAI that im hearing the cylinders turn on and off because of AFM? i used to have a range v8 but i sold it because im getting my mods this week and im tuning it next week. i think im being a little paranoid but has anyone else heard a weird noise from a new METAL intake and having AFM still on? just making sure its from the change of intake being that metal intakes are louder and echo more engine noise and my AFM is no longer disabled. its not throwing any codes and it runs great just so you know. i hate AFM i cant wait to have it off for good!

[Denis]

ummm idk about that. the AFM transition shouldnt have a "clunk" associated with it.

[tohper]

I have the same intake as u op. Also have a range. Ill listen to it when i get off work and let ya know.

[bigssc]

Originally Posted by Denis

ummm idk about that. the AFM transition shouldnt have a "clunk" associated with it.

its not like a hard clunk im just describing the sound very terribly lol its more like a swoosh-thud lol very light and only happens when im at very low speeds and than give it gas to speed up and it didnt happen and i never heard it when i had my range v8.

[bigssc]

Originally Posted by tohper

I have the same intake as u op. Also have a range. Ill listen to it when i get off work and let ya know.

ok great unplug the range and see if u hear what i hear. its only at very low speeds between 20 and 30mph and then just give it a little gas to start speeding up its a very light sound most people probably wouldnt even hear it lol and like i said i never heard this with my range plugged in

[FanDamNCSU]

Probably is AFM. I can hear when my AFM kicks in.

[vroomapunk]

Originally Posted by bigssc

its not like a hard clunk im just describing the sound very terribly lol its more like a swoosh-thud lol very light and only happens when im at very low speeds and than give it gas to speed up and it didnt happen and i never heard it when i had my range v8.

Swoosh thud is a good description.

Its the intake sucking up a bunch of air, then you abruptly letting off the throttle so the pressure changes drastically and has to go somewhere.

The CAI inc cai is a sealed box, so itll make this sound more dramatic than the K&N because of even less of a place for the pressure to go.

I get the exact same noise when shutting my car off, everytime. I dont hear it when im driving really, but I have headers and loud exhaust.

Next time you turn the car off, roll the window down and listen for it, if its the same noise you hear when you drive, then its normal!

[MrWray]

Ive got the CAI on mine and ive never heard a clunking noise

[bigssc]

Originally Posted by MrWray

Ive got the CAI on mine and ive never heard a clunking noise

like i said in above comments its not a clunk its more of a "swoosh thud" lol if that makes any sense. what ever im not worried it must be normal because the car runs perfect and only has 2,800 miles on it. its def from the new intake and taking out the range v8. i put on the range v8 at 700 miles so i never really experienced much of the AFM and its weird bullshit that it causes. im sure once its tuned i will never hear it again because the AFM will then forever be turned off.

[vroomapunk]

Originally Posted by bigssc

like i said in above comments its not a clunk its more of a "swoosh thud" lol if that makes any sense. what ever im not worried it must be normal because the car runs perfect and only has 2,800 miles on it. its def from the new intake and taking out the range v8. i put on the range v8 at 700 miles so i never really experienced much of the AFM and its weird bullshit that it causes. im sure once its tuned i will never hear it again because the AFM will then forever be turned off.

Read my comment above, I believe it is normal operation of the CAI, I get the same noise when I turn my car off and its perfectly normal.

[bigssc]

Originally Posted by vroomapunk

Read my comment above, I believe it is normal operation of the CAI, I get the same noise when I turn my car off and its perfectly normal.

thank you! i read it and i appreciate the help and my worries have been soothed

[danl]

JRE tune took care of that dam AFM for me!


that AFM noise became worse when I deleted the resonator, and put a 3" exhaust with X pipe....Tried to live with the sports mode shifting thingy, but that got old real quick.
Good Ol Ted at JRE, his tune killed that awful AFM, and helped with the shift points, and keeps my radiator temp no higher than 198, even in Hot Ass So Cal summer.
This is the sound, and performance Chevy should have gave this car from the factory.
With the Vmax TB, and K&N cia, this car kicks ass over lexus, Infinity, BMW, Chally, 4.6L mustangs, ( have not had the chance to dice with the new 5.0) on the freeways. its amazing to just 'walk away' from these guys in their so called luxury cars. I think they watch these commercials, and actually believe they can blow away everyone while lapping in the luxury of their cars. . . then they meet the JSB Camaro, blue devil!

[markmass]

I think your in good shape - you will definitely hear more air being sucked in, there's your 'whoosh' the 'thud' may just be the air in the intake bouncing around, should not really be 'thud'. My first mod was the CAI, i really cant remember a 'thud'
Not sure about the responses about AFM, that will not kick in under acceleration but I had mine tuned out long ago, plus bad memory....

[Kiteboarder85]

Def normal. LIke the comment above, its the noise like when your turn off your car and your CAI sounds like it sighs before it goes to bed.