Not Your Everyday Vibration... HELP?!
 

So just as a few days ago, my car has been making a weird vibrating noise. Let me describe it to you the best I can.

After testing certain things, I have concluded the vibration only happens when I turn the cabin air on. This isn't a usual a/c rattle/vibration though. When my car idles, it doesn't vibrate, but when I rev the engine and accelerate the vibration comes and goes randomly through the rev range. It never comes and goes at the same RPM. The sound is best desribed as a corresponding vibration to the tone of the stock rotary engine (goes up as rotary winds up and goes down as it winds down), but it is a bit louder and more buzzy like one of those wind-up toys you turn the key on and then hold in the air as it unwinds. Anyone have similar experience with this? Or possibly know what it is?

Thanks in advance!

Noone??

do you feel a vibration in the shifter when in netural and with the A/C on?

Nope. There is no real difference in feel. It is just an annoying buzz/vibration that kicks on and off at randome times as i accelerate and decelerate. It's not like it is a random buzz that isn't a problem... it is def. with air on and happens when I accelerate and then winds down with the engine and goes off at a point... It is def. noticable without music on.

edit: I'm at 52,000 miles, so hopefully I can get all your help to avoid a post warranty dealer visit.

compressor taking a shit? i'd have to hear it.

That's the thing... you do have to hear it to have a clue! It's such a weird noise to describe and for as long as I've been reading these boards, I really cannot pinpoint it to anything I've heard on here before. I was just hoping someone knew...

Maybe something is loose and vibrates at a certain frequency that only happens when the A/C is on? I'd go through the cabin, engine compartment and trunk and check to see if anything is loose that might be causing it: a screw, a fastener, top of the shift knob, something sitting in the glove box or console, etc.

Check the cabin filter.
Maybe it's clogged.

So I took the two filters out and cleaned them (they were extremely dirty), but to NO avail. The noise is still there... Anyone else have other ideas?