So not too long ago I noticed my engine bay would vibrate/make high-frequency buzzing noises when reaching a certain RPM (would happen between 4k RPM and when the trans shifts up).

So I came home one day, popped the bonnet and gave the throttle cable a few tugs. Nothing. Sounded awesome and loud.

Drove it the next morning, happened again driving home in the arvo.

It now makes the noise either from ~2k RPM upwards, or happens around 2k and then again when its a bit faster.

Is my transmission boned? I got some trans fluid today and topped it up a bit (was at the cold marker when it was more than hot) and that hasn't done anything but go all over my driveway and around the ATF spout (ended up removing the snorkel..)

Cheers guys, this is not only hampering my ability to pick up chicks with my sick lad 3.5 V6, but I get the feeling impending doom and a seized transmission or something crap like that will strike at a really stupid moment, like idling in a maccas drive thru at 3am or something.

Hey fella, I am no expert but would suggest a full flush and service if you haven't done it lately, just let them know about the problem when you drop it in there, could be perhaps fixed with service and flush?

Sounds strange.. have you checked the engine mounts? Does the transmission slip/jerk during gear changes?

I think the slightly-less-than-full fluid level in the transmission was causing it. I bought a 1L bottle of fluid for testing (and because I'm a tight arse) and squeezed a tad in. Sure enough took it for a drive and it eventually sorted itself out by night time (so I could do some sick lad laps in town without sounding like a douche with a boned engine).

I'd figure that something is vibrating at the frequency the same of your engine at 2000rpm. Maybe exhaust or something that hangs off the engine...it's called sympathetic vibration. I've seen handbrake cables, seat bases, dashboards etc do this in different cars. If an engine mount has failed and you have metal to metal contact the vibration would be more pronounced I'd guess.

Doesn't even sound like a transmission fault to me. It sounds like something else. No idea what, but I dont think its your box