Let me preface this by saying, this is 100% definitely not clutch buzz. I have the decel clutch buzz, I can easily recognize it, and this is NOT it.

Ok here we go.. I took some back roads off home from work today so I could do some spirited driving. I hit 7-9k a couple times and I was cruising at 4-5k in lower gears. Shortly after I heard a very loud, slightly erratic, buzzing noise coming from behind the dash/cluster (NOT near the tranny) on deceleration from say 4300 to 3200 rpms. My best description of the noise is a mix between a 10ft bumble bee and a weed whacker. I heard it in 3rd and 4th gear (didn't check the others), but I highly doubt this has anything to do with the drivetrain. I know the car makes many noises, and generally I think nothing of it if I hear something slightly out of the ordinary, but this made me say ok what the F**K is that.

It could be something right near the fire wall, but it really sounded like it was inside the dash. I started the car back up about 10 minutes later, revved it a bit in the driveway, and took a quick drive but I could not reproduce the noise. Even if it never comes back, I wan't to know what it was!

 

I've heard something like you've described. It ended up being the little plastic cover on the rear view mirror bracket. I was amazed that little thing could make so much noise.

 

the rear view or the side mirror?

 

The rear view... there's a little plastic cover on the bracket that is stuck to your windshield. It's on the '05s...I didn't think the mirror changed from model year to model year.

 

I've had a buzz like that for a long time that I only heard in conjunction with the clutch buzz. I finally figured out it was coming from the passenger side visor. I placed my hand on it and the buzz stopped.

Now I just regard it as one of those little things that give the car its "charm".

 

hey man i think i recently have come up with this same sound. It only happens once in a while not all the time and i prolby couldnt duplciate it if i wanted to. Id also like to find out wut it is.

 

Do you still have an oil cap installed?

 

I checked the oil cap. it was on tight. the noise is definitely not coming from the rear view or a visor. It's either behind the dash or from the engine bay close to the firewall. It's clearly centered in that area. It was raining today or I would have poked around more, even though I only heard the noise a few times yesterday, and zero times since.

 

I had a similar noise... my Comptech intake carbon lid screws had come loose and were letting the lid rattle.

Do you have a Comptech intake?

 

Is your A/C fan on by any chance when this happens?