Whistle on accelereation

2008 Prerunner, 4.0 Liter, V6, Manual
I have NO check engine lights on.
Bluedriver does not read any codes.
Called the dealership, they say it's nothing.

The truck has a whistling sound on acceleration. Sounds like I have a turbo.
What is going on?
Checked for any issues with the air intake, can't find anything.
Am I just going crazy?

 

I had this problem after I installed a joying head unit. It drove me crazy, so I put the oem back in. Not saying it’s your radio but maybe in the same vein.

 

Does it only do it under acceleration?
Or cam you get it to do it when you are stopped, and just rev the engine?

Are you running the stock air box?
I’ve heard this same sound on “cold air” intakes.

Any leak before the MAF sensor usually won’t throw a code, since it’s being metered.

 

The only addition to the head until was a Bluetooth module that I placed behind the unit.
I am running a stock airbox.
Acceleration is fine.
As long as the engine is on I hear the whistle.
The whistle is only annoying because I am concerned, it is a leak behind the sensor.

 

Could be an idler pulley, mine sounded like I had a supercharger.

 

Take the drive belt off and see if the noise is still there

 

Alternators tend to whine right before they fail. Check your charging system.