Can anyone help me identify this sound (Video inside)?

Quick background - this whistling sound appeared suddenly after having the driveline TSB completed (and having the truck washed) at my local dealership. The next morning I woke up, remote started my truck, and came out to this sound. By the time I was out of my neighborhood (~2 miles) the sound was gone.

It showed up again the next morning and again disappeared by the time I was out of my neighborhood. I took it back to the dealership for a look - they told me they couldn't replicate the sound but they were "100% sure" that it was the air intake pump taking in air. I told them it sounded more like a belt but they weren't having it.

The sound only appears if it rains the night before - but I can't put my finger on it because I am mechanically-retarded.

Help - excuse the length of the video but you can skip to the :30 second mark to get right into it.

https://www.youtube.com/watch?v=m6Y6eArikP4

Oh yeah, 2012 Tacoma DCLB Sport package.

 

I should also note I'm just looking for feedback for me to tell a mechanic to point him towards possible issues - not looking to fix it myself.

 

Belt. Idler Pulley or any pulley for that matter, Mechanic should know how to find the one

 

90% sure?

 

I'm pretty sure that's what it is. The belt squeaks until it warms up, then stops. Reading your description it sounds like it also squeaks when there's high humidity. Try tightening the belt or replacing it...

 

Cool, thanks. So what I'm saying to them is the belt idler pulley needs tightening/replacing?

 

I had that same issue with my 2008 taco. Took it to the dealership and they replaced both the upper and lower idler pulleys. It fixed the problem and haven't had any issues since, and that was almost 3 weeks ago. Hope this helps.

 

Thanks for the help everyone. I took it in for an oil change and mentioned the above - they inspected and replaced the idler pulley belts (both), citing that they were "glazed".

 

Did it fix the problem?...

 

You have two problems, most likely one is a serpentine idler or the alternator (the squeaking one), the other will not go away, it's the reason mine was lemoned. Search for posts under hotrod53 and you'll find my posts on it.

 

Found your thread and sound clip:

http://www.tacomaworld.com/forum/2nd-gen-tacomas/317054-13-v6-4500-miles-my-motor-may-shot.html

and

http://s154.photobucket.com/user/hotrod53/media/IMG_0782trucknoise_zps688655bc.mp4.html

I'm really sorry that happened to you but sounds like you got a new truck out of it plus a lot of heartache. I listened to your clip a few times and that sound isn't familiar to me. I haven't heard my truck make anything like that before the belt squeal and haven't heard anything like your clip after getting the belts replaced.

I'm going to monitor it because I may not have been listening for it but it definitely doesn't sound like your issue from the outset.

 

Today was the first day of a significant rain so, ergo, the first real test to see if this problem was resolved. It was. So for those finding this in search the solution was replacing the idler belt.