Engine whine while in park, neutral, or drive

I'm at a complete loss with this noise folks. Hoping someone has experienced the same isuue... So this past weekend we took the truck offroading. We wheeled it moderately hard but nothing out of the ordinary. On my way home I noticed a whine while driving. It sounds similar to a steering pump going out or pulley. It is more noticeable when slowing down, and really hums between 20mph - 60mph. The same sound is heard when in park or neutral starting at about 2500 rpms. The dealership looked at it and said they couldn't located the source of the sound. Alternator and pulleys were checked and they said everything looks good. Any help would be great. TIA

2019 Tacoma TRD OR 4x4

 

At least the dealership has on file that you took it in, hopefully whatever it is shows itself before the warranty runs out

 

FYi old trick from good Mecanic’s is they use hearing prob to listen where a noise is coming from when engine is running hope that helps good luck

 

Wait are u one of the ones that got the Magnuson super chargers installed? Is it that? It's not your transfer case right?

 

I do not have a super charger.

 

Did you go through water while wheeling?

 

No I did not.

 

There goes my theory.

 

probably need to grease your driveshaft and check your differential fluid

 

A newer trick is using the NVH app while driving...but it's not really priced for your average shadetree mechanic.

 

Torque Converter?

 

@Medcomm, it could be your torque converter if you have an automatic.

Offroading is really tough on the torque converter because it's constantly going between being hooked and unhooked. Mine started making noise after I wheeled too hard all day. A few drain/fill cycles of the transmission later fixed it completely. I also took the time to add an auxiliary cooler to the transmission when I did so, the factory cooling isn't enough for sustained offroading in hot weather with a loaded truck.

 

Take the serpentine belt off and start it up. If the whine is still there, it is internal to the engine or in the transmission.