Buzzing sound driving me insane (I know ... short trip!)

'04, M/T, 2WD, 140K miles.

A month ago, maybe after driving on a rough road, I started getting a buzzing sound in the interior starting at 2,200 rpm. Seems to be coming from the driver side near the dash, but I can't find anything loose, even removed the instrument cluster and air duct that runs under the steering column ... nothing seems to responsible for the buzzing. Checked under the hood and under the truck, no obvious sources. Driving me insane!
Thanks.
Ken

 

5VZFE engine?

 

2.4 L 2RZ-FE

 

Is this another case for the importance of a working radio and turning it up?

:-D

I have a couple of those actually, obviously not bad enough to drive me nuts (my walk is shorter than yours I think.) As long as it's not something mechanically wrong it's not worth the trouble to chase it down. It could be anything, short of tearing the whole dash apart (which you've almost done) you may never find it. You might consider looking in places you don't expect. It may sound like it's in the dash, but maybe not. A member here had an odd sound and was sure it was in the dash, turns out a rusted disc brake guard was blowing around and contacting something.

 

does this 'buzzing sound' occur at 2200 RPM in most gears or all gears?
does it go away after a higher RPM is reached and then comes again on the next gear shift?

these pesky resonant sounds do like to travel LOL...

 

With column shifting on mine, there are three/ four solenoids around that area..

there's key inter lock one right next to the ignition switch....

there's brake safety one to prevent shifting on the column....

and there's actually two of them in the open circuit relay....

all those located right there in that area.

never heard of them ever buzzing before.....you could be patient 0

 

It occurs in all and no gears ... even in neutral when the truck isn't moving. Frustrating!

 

Is your truck lifted and/or are you running aftermarket leaf packs?

 

Stock suspension. Stock everything

 

Buzzing and rattles drive me insane. Here are some things that I have found or checked over the years:

-loose spring keepers on leaf pack
-manifold, cat and exhaust heat shields (usually rusts out around a bolt, or a rock gets caught in the clamshell)
-brake line rattling from missing spring clip
-exhaust clamp too loose
-busted welds inside muffler allowing internals to rattle. Check cats too for busted honeycomb welds
-Loose skid plate bolts - plate rattles, or stripped threads allowing bolt/washer to rattle

Sounds travels weird in these trucks and even stuff in the rear of the truck often sounded like it was coming from the front

These are the ones I can think of off the top of my head

Don’t even get me started on clunks

 

Thanks Brian, Bill, MD, others! Those are some good areas to investigate.

 

Good luck, let us know what you find!

 

Problem solved! A "zen" mechanic found that the large-diameter duct (air intake/inlet hoses and resonator) between the air cleaner housing and the intake manifold was slightly loose. I removed it, cleaned all the mating surfaces, reinstalled, and tightened all the clamps. Strange how that little bit of vibration had resonated through the interior!