This has been bugging me for a while.

Basically, whenever I'm inbetween 6,000 - 6,300 RPM, I hear this "static"ish sound (Nothing like MIAC) coming from what sounds like directly in front of me, as if it's inside of the steering wheel or something. I only hear the sound inbetween these exact RPMs. I'm pretty sure that this sound is only heard when the engine is under load, meaning I don't hear it when revving in neutral, but I'll have to make sure of this later today or tomorrow.

None of my driving seems to be affected by this.

Info:
2007 Crystal White Pearl
Base Model, Manual
approx 11,500 miles

Sorry if I'm being too vague, but this is really all that I know. Weird static sounds inbetween specific RPMs.

 

Sound system off or on at this time?
A/C and fans on or off at this time?

I read what all you said, but the above two things might also be interesting to know.

 

Something in the instrument cluster vibrating and buzzing? My Miata's instrument cowl did this. I think it was the plexiglass vibrating in its housing.

Just a thought.

 

I hear the same thing at the same RPM's, under load (not revving) and it's right in front of me. Very audible. It has been happening for about a year now. Mine's a stock '05 6spd w/ 35,600. It used to bug the hell out of me, but I let it go after seeing no one else with the same problem......until now. The car doesn't seem affected by it at all but when you're getting up in the RPM's that noise doesn't sound good.

 

Had same noise coming from area you described and mine's a RHD version so it sounds like its coming from behind the glovebox/radio area. Opened up centre console, shifter console, glove box, radio area and made sure everything was secure, noise is still there. Checked for loose heat shields in the exhaust manifold and cat area, no issues, noise persisted. Mine sounds like a resonating sound and happens only during acceleration (when revs are increasing) and not when the revs are falling. More audible when loaded and happens only when the engine is warm. Louder when its hotter. Brought it to a garage, they attached listening devices and said that its a crack in the exhaust manifold.

 

this will sound strange but check the rotor trim in the seat headrest. when you hear the noise reach behind you and press on that trim piece. If the sound stops, Im a genius


also it could be a loose nut between the seat and steering wheel

 

Also small sand or rock chips can make it in between the steering column and the plastic.

Move the column up and down and clean it.

 

Had same noise issue..same rpm range...and the sounds like coming behind the firewall closer to the gas pedal..and this happen after i do the following..
Monday-Go to the dealer for the oil change and Recall (Reflashing-tech said i had the latest PCM flash so they do nothing about it)

Tuesday-do my tune-up so take out ignition coils first and i broke one of the bolts..so i take out the air filter box (for extra space) and remove the plates that holds the coils, bang the bolt,replace a new one and
epoxy it (am not sure if i had a grounding issue with the coil in this specific location)

Wednesday-Install new coils(OEM-updated),wires(bigger ones),plugs(OEM)..put back air filter box...cleaned MAF sensor...flush coolant...drive to hi-way and here we go the static noise..A/C off..Radio off..Fan off...

tomorrow(saturday) i will check it if i miss something( losse wires?...loose hose?)

 

meh i wouldn't worry about such little things. if you get a loud enough exhaust then you wont have to worry about hearing things:P

 

Strangely, mine happened one day after putting on larger ignition leads and changing the plugs. I also had a workshop top up the aircon refrigerant. This made me second guess my installation. You mentioned breaking a bolt. Check the bracket that holds the coils to make sure its not vibrating. I checked mine, its fine. Noise still there. Did you find that the larger cables were a little too big for the cable bracket? Wonder if it could be caused by tightening the plugs at wrong torque...

 

Guess what, the other day, I head this new noise like a "loose plastic panel" knocking and it sounded like it was coming from behind the instrument cluster but near the windscreen edge. Eventually it turned out to be the lower dash panel (that piece of plastic under the steering column that is held by 2 A-clips and 2 hooks). Apparently, one of the hooks was broken. Attached some foam tape there and its gone. You are right, noise in this car always appears to originate from a different location. But the other vibrating noise is still there.

 

ya..the new cables are too big for the cable bracket(holder).. i tighten it with a #18 solidwire..