Acceleration rattle

Hopefully you didn't get a tank of bad gas. A rattling sound can be preignition. It sounds sorta like a can of marbles being swirled around.

Did this just start having this problem and/or did you recently fill up?

 

Open your hood and check the rod that's used to hold it open. If it's not clamped properly in place, apparently it can cause a rattle.

 

Bingo,
last time someone reported what your describing, that was the problem

 

This topic hit my 1+ year old Gen III. It's been pretty much free of rattles - of course squeezing the console bridge or touching plastic dash areas brings out creaks and such.

But, yesterday - out of the blue, a buzz when accelerating. Not a definitive pattern, but definitely relates to normal car vibrations - ie when the ice is operating. Typically starts between 20-25mph. Is a buzz, not creak or rattle. And can increase in pitch, perhaps with more car vibration. It is definitely located in the passenger side dash - almost like where the air bag is located.

I have removed EVERYTHING out of the glove boxes, sunglass holder, and door pockets. Have taken the lower box completely out and taken test drives. Has nothing to do with radio or A/C - both off. Checked the hood prop rod. All the typical fixes tried that have been noted here.

It was buzzing just now in Park with the ICE on. The buzz sound can fluctuate and sounds more like marbles on a pie plate (of course not THAT loud, but that muffled type of sound). Again definitely from the middle of the internal pass dash area.
Going on a 2 hour trip tomorrow - will have the other person drive and I'll try to better diagnose. I HATE creaks/buzzes/rattles in a car. Just makes the thing feel cheap. Hope this isn't a sign of the future... the dash plastics and assembly has me concerned for ongoing noises as the car ages.

Any ideas or anyone else have/had this buzz?

 

RETRACTION from below.
I come back embarrassed. The buzz problem came on suddenly; and I was quite upset as I hate rattles and noises in new(er) cars. It was close to maddening. And as I said I had looked at and tried everything learned by others on the site.

Thought I'd look under the hood once again. Yep that darn hood proprod is up and snapped. Nothing loose around the wiper area.

By chance, I looked down at the front passenger side near the parking light. And touched the air inlet hose. It moved... And the mounting bracket was loose. Bottom line, I had re-replaced LED lamps in the parking lights a couple days ago. Apparently when I reinstalled the air inlet hose assembly, I put the mounting plate on the wrong side of the hex screw. Tightened the screw, but the plate was just hangin' loose on the nut. I installed correctly - and thought OMG if THAT was the problem.... It was. The source of the buzz was about 3' in front from where it sounded - in the passenger dash area. Took it for a ride, and quiet. Now I see how the prop rod can reverberate and sound like a dash rattle too.
So the problem was caused by...me. Sorry Toyota for all the %$&*@# things I called you. Never mind.

 

^ Glad you figured out!