Front end humming/whirring

My 2nd gen tacoma has been making a bizarre humming/whirring noise. It's intermittent, and loudest when idling in drive with my foot on the brake. Becomes higher frequency with increased rpms but becomes indiscernible from normal engine noise pretty quickly. Weirdest of all, it's pretty loud in the cab, but I cant hear it at all outside the vehicle or under the hood. Any ideas?

 

Recording? Are all of your fluids topped off? Which motor? Mileage? History?

So many details it's hard to sort through them.

Steel is also an excellent conductor of sound, more so than air.

 

wheel bearings maybe

 

Idling in drive with foot on the brake . . . fool.

 

Idler pulley? Pull the belt off and see if the noise goes away

 

Wow...a tad harsh perhaps?

 

Where do you think the noise is coming from? Engine compartment? Behind the cab, maybe like a fuel pump whining?

When you are idling in drive foot on the brake, does the noise stay constant or is it cyclical (i.e. noise happens for a few seconds, then goes away a few seconds, and repeat)?

Anything else you can tell us? It's going to be difficult to answer for you over the internet but more details are better. Finding phantom sounds is always a challenge even when in person.

 

I missed that part! Most like not related to your drivetrain then!