So I finally got the sound recorded.See video below.
The sound occurs at 00:45. I can describe it as a buzzing sound but cannot pinpoint what the cause it. Also I only hear the sound 3-4 times a month, and can't recreate it. Has anyone ever heard a sound like this? 2006 MCS

 

My ears are not the best and I did not hear anything around 0:45. You down shifted about that time correct??

I just told another poster that you have to remember that a Gen 1 Mini has more snaps, crackles and pops than a box of rice crispies. In your opinion is it inside or outside?

 

It is easier to hear with headphones on . I am not downshifting at that part, I am accelerating(probably in second). Sounds like the outside for sure. It is also strange because the volume of the sounds changes. Sometimes it will be really loud and freak me out.

 

I heard it and it freaked me out, sounds like someone is saying, "YEAH" in a reverb voice...and it comes in at 46 seconds.

 

To me, it sometime sounds like an old school ahh-ooogah horn but a horn that is slowly dying... maybe the car is possessed .

 

Sounds like the throw-out bearing

 

Wouldn't the sound occur during shifts if it was that? This happens just while accelerating/cruising.

 

Would be better if you backed off the camera so we could fully see what you are doing at the time of the noise. I can hear it with earbuds just fine, just need to see what you are doing with pedals, steering wheel and gear shifts, while seeing tach and speedo. Could be something as simple as resonance from exhaust component which is loose or misaligned heatshield.

 

Did you ever find the cause of your noise?

 

Nope. The other day I was able to get the noise to occur consistently awhile reving up through 1800 rpms in 3rd gear. I tried all other gears at 1800 rpm and there was no noise. The next day it was completely fine...

 

I can definitely hear the sharp higher pitch noise at 45. Sound to me like caused by thin sheet metal vibrating. I had similar problem with my gen 1 miata. In that case was a hairline crack on the stainless steel heat shield for the exhaust header. It is very common for weld joints on stainless steel sheet metal to fail from fatigue. Baffles inside muffler and resonator can also cause similar sound that happens at a narrow vibration frequency band.

 

That os a good idea. I will see what I can find

 

you can also hear it at 2:48...im not too familiar with 1st gen, but can you tell whether the noise appear with AC on or off? can you look for that noise while stationary?

 

Ac has been off when I have heard it. I cannot create the sound whole stationary. I plan on looking through the exhaust and heat shields soon.