Whining noise when idling what can it be

Hi Tacoma world! My 2002 Tacoma Prerunner has developed a whining noise when I'm either stopped at a stoplight or stop sign. But when I accelerate it goes away. I checked and belts seem fine and fluids are normal. Any idea on what it can be? Everything runs normal and it a V6 3.4L engine.
Thanks

 

Check your idler

Where in general is it coming from?

 

Generally from the engine bay, thinking maybe power steering pump, possible low fluid but look fine. Also maybe thinking about a clogged transmission fluid filter.

 

Agree with previous advice to check idler pulley first. Automotive stethoscope could help pinpoint general location of this whine

 

Alternator.

 

I am experiencing the exact same issue, exact same trim Tacoma, my alternator was just replaced 5 months ago.
When I let off the brake pedal, the whining sound greatly decreases.
But definitely audible when stopped.

 

Belt, pulleys or alternator are common whiners.

 

did you ever diagnose the problem? I’m having similar noise that I would describe as a howling at idle. Of course it doesn’t always make the noise. It comes and goes. Sometimes loud, sometimes barely audible, sometimes no noise at all. Something is definitely wrong though. I’ve taken it in twice over the last month and it wouldn’t make the noise for the mechanic either time. It’s like the truck knows and it’s screwing with me. Any help would be greatly appreciated thank you

 

Same here. Any updates?

 

What transmission is in play here?

If manual, it could be either the pilot or throw out bearing going out.

 

FWIW, The power steering pump on my Volvo whines. It's coming up on 200k and it has had a low whine for as long as I can remember, but no leaks, original rack and maybe add a couple of ounces of fluid once per year.

 

It would help if you held the computer a little closer to the truck so we could hear it.



Kidding aside, a video clearly showing the sound would help.

A whine is usually the PS pump, especially if it comes and goes. You can easily hear it from that area if the hood is up. If so start with flushing it and cleaning the reservoir screen. It may also change pitch as you turn the wheel.

A shriek/squeal can be belts or alternator bearings. Mine would do a shriek only now and then on startup. As it turns out the alternator belt was not quite tight enough.

If you're experiencing this only when the brakes are on, it could be the master cylinder. If it's an auto, there may be something up with the tranny but it's pretty easy to tell it's not coming from the engine bay.