RX8 pearl red

Hey all.. Any one experiencing deep and little loud bass exhaust OR intake sound between 3k to 4k rpm with stock intake? its kind of a droning sound.Mine is doing it and and it starts at 3k rpm and vanishes after 4k rpm. Need suggestions.. its not a whistle sound. Its a silent continuous vibration on neutral 3k rpm revving which turns to drone sound at 3k rpm while driving.

RX8 pearl red

No one? if i rev it at 3k while stationary, i can still feels the NVH in all areas from the car.. checked motor mounts and they looked Ok

RX8 pearl red

Finally confirmed the diagnosis from a good mechanic here. At neutral while revving to 3k, Maximum vibration was felt only on upper intake manifold and VFAD box. The same vibration with less intensity is transferred to the chassis and it became more clear while driving between 3k to 3.5 k rom.
My mechanic told me that charged air coming in the Vaccum chamber and manifold is causing these vibrations in the manifold but i wanted to ask you guys about you opinion that which part in the manifold can cause this? so that we can sort this out after opening up the upper intake manifold. Now that all of you know the problem area, let me know the best educated guess of which of these areas can cause this and how to fix this.... thanks

RX8Soldier

iTrader: (24)

Check the maf screen that it didn't come loose. It's in front of the maf sensor.

Your ssv could be causing the issue. You're not getting any CEL?

RX8 pearl red

No CEL watsoever. Maf screen is intact and not bent either

RIWWP

iTrader: (2)

You aren't describing a problem that I have ever seen anyone talk about in my time on the forum. Either you found a really strange and unique problem, or there isn't actually a problem you just think there is, or the problem isn't actually what you are describing.

RX8 pearl red

Well sorry for that. i tried to best describe the problem and that is when revving at 3k to 3.5k in neutral, something seems to be vibrating in upper intake manifold and it feels like air is not passing by freely and creating a silent vibration.I touched everything under the hood and the maximum vibration is felt only in this area That same vibration turns into drone sound while driving at 3k to 3.5k on all gears.

Can you mention how to take apart the upper intake manifold and see whats in it or i just have to clean the SSV only? what parts are inside upper intake manifold?

RIWWP

iTrader: (2)

No parts inside the upper intake manifold. The DIY for removal is over in the DIY section, a search of the site with google will find it.

The engine has combustions, and will thus always produce some level of vibration. Air moves, resonates, pulses happen with intake and exhaust, etc... There ARE always resonant frequencies for these things in any car, any engine.

What you are describing doesn't even sound like a problem to me, but maybe they are heavier vibrations than you appear to be describing. To me, there is no vibration possible in the intake from air resonance that would ever bother me or make me think that there is a problem. Air pulse generated vibrations would always be really small and low. If it's not small and low vibration, it's not air. If it is small and low, it doesn't sound like a problem to worry about.

RX8 pearl red

Yeah i think you are right. Just now a good mechanic here told me that i am wrong about only intake vibration. He told me that he is feeling vibration on whole car and motor and it is the engine own vibration that is shifting to the whole body and mounts ( even if they look good) are not doing their job properly to cut that vibration on certain RPM i.e 3 to 3.5k. So, i guess i have to live with that or i have to put in new set of mounts. IDK

RX8 pearl red

Finally sorted out. Gear mounting and one motor mount was causing the vibrations and droning sound at certain rpms