OK, here is a real odd problem. I am on a trip from California to Arizona, speed limit at 75, so often over 80. At about 80-83 mph a noise comes from the dash area, driver side, but only when throttle is pushed. In other words, if I am going 85 and accelerate, I get the sound, but if I ease off the throttle, still doing 85 for example, no noise. Step on accelerator again, even slightly and there is the noise every time. Never below 80, always above.
The noise is a vibration-buzz sound. No feel of a vibration, just a sound. I notice no performance issue at all, only the sound. Very irritating. My buddy riding shotgun says it sounds like under the dash on driver side, to me it sounds like coming from air vents location-wise.
Ideas?
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09 V6 Pony Convertible Daily Driver-- Have: FRPP X pipe true dual exhaust, Eibach Pro-Kit lowering springs, Steeda camber plates, Steeda strut brace, and some dress-up stuff Next: C&L intake Bamachips combo, 4.10 gears + LSD.
I seriously doubt that it has anything to do with anything in the dash or vents. Sounds are funny that way though and can decieve you on their location due to the resonance of the dash or vents. It probably has something to do with your transmission, or drive shaft in some way, mabye a slight imbalance in the driveshaft, and a heat shield is vibrating, or the u joint may be shot. bummer is that just about the only way to prove it, is to put it on a dyno and find it while under said load. Not a safe proposition, so start with the easy stuff, check clearances between exhaust and driveshaft, trans and exhaust, and check for play in the yolk to the trans.
Hope you find it, wierd sounds pisszle me off. I am sure I am not alone in that.
You could spend hours ripping apart the console and dash, removing the instrument cluster, radio, etc. and re-tighten everything, adding dynamat in between panels that are close together and hope that you fix the problem.
Or you could just drive the 75mph speed limit and not worry about it.
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Black 2005 Mustang v6, 5 speed, IUP, EUP and Leather.
Razzi 1/4 window scoops, Mustang GT Sway Bars, Flowmaster American Thunder Single Exhaust, Clear Front Turn Signal Lenses, Demolet CAI, X-cal2 91 tune, Hurst Comp/Plus Shifter, FRPP T-Lock, Ford 3.73 gears
The way you can tell if it is the dash, next time you start to hear it vibrate, reach to the very back of the dash, almost to the bottom of the windshield, and press firmly. If the vibration stops, you've solved the mystery. Mine did the exact same thing, and thats what it was. Just just left it alone though, my exhaust at that speed makes it impossible to hear anyways.
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2006 V6 auto with the pony package
adding to it everyday
All of these are possible I suppose. But it is very odd how I can tap the accelerator above 80 and there is only noise when peddle is depressed, not when I let up, even maintaining the same speed. I can tap five times in a row and every time the noise is there when pressed and not there as soon as I let up.
Any additional ideas appreciated.
Thanks!
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09 V6 Pony Convertible Daily Driver-- Have: FRPP X pipe true dual exhaust, Eibach Pro-Kit lowering springs, Steeda camber plates, Steeda strut brace, and some dress-up stuff Next: C&L intake Bamachips combo, 4.10 gears + LSD.
The noise is because the S197 dashes are cheaply made, i think they solved this problem on 2010 Mustangs, i have a 07 with 3000 mile and i get the noise, rattle from everywhere when i gas it while cruising.
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07 Mustang Pony pkg 4.0L V6
Appearance: Roush hood scoop, rocker panel, custom GT500 chin spoiler, side louvers, racing stripes, shifter bezel, door sill plates, Sequential tail lights
Performance: C&L intake, Bama/Tillman 91 Race tune, SCT X3, Mac dual exhaust kit, OEM Ford 3.73 gears/T-lock on 7.5'
i'm still pulling for the drive shaft idea. It really could be anything though. if you ever feel the need to do some more performance mods, get a new driveshaft. Will make the ride a lot smoother and adds about as much power as an axleback exhaust
After 70ish MPH, the car starts to "whistle" like a tea kettle.. thats the only way I can explain it.
I brought it to the Stealership, but of course they said everything was fine and charged me for labor..
I had the exact same problem with my 98'. It always happened at 70 and only when I began to speed up....even if only a little. I had the car for 10 years and it never cause a problem....except killing my nerves
Odd Noise over 80 MPH...HELP! 
