Help diagnose sound (3rd Gen)

2019 3.5 V6 with 29,000 miles.

Took my teenage son out in the woods to have fun on the Bilstein 8112/8100's. Splashed through a bunch of puddles from recent rains. We were really dive bombing some of the puddles. When we got back to the main dirt road my son (has his permit) wanted to drive the 4 miles home on the graded dirt road. When doing to driver swap we noticed the sound. Not sure when it started. Had music going and windows closed during the drive to keep the water out.

The noise is loud whenever the gas pedal is used and often slows down or dies out when coasting. At idle it is sometimes there and sometimes not.

This may be related or may not be, but I've been hearing a high pitched subtle whine at times while driving. I only hear it once or twice a week and it only lasts for 2-3 seconds. I keep thinking it may only happen when the A/C is running but it comes and goes so quickly at a rare frequency that I don't have time to turn off the A/C to see if it stops the whine.

I'll be taking to the dealership as soon as I can.

 

Idler pulley? Hard to hear

 

Take a tiny amount of water and toss it on your belt when it's on. If it stops your belt had some dust in it. Mine did this on and off for a couple of months and hasn't done it in a long time after the water trick.

 

Water tricks works for a minute or two and then noise starts coming back. You are on the right track!

should I try wetting other pulleys?

 

Had a very very similar sound. It would come and go. Watering my belt fixed it for a few days at a time. I figured I'd start with putting a new belt on and that took care of my noise. Never replaced a belt before and doing it on the taco only took me 30 minutes.
Starting around 30k the squeaking would come and go on its own during the summer. Got really bad this summer (like in the video) at 45k.

 

If it goes away when it is on the belt then it is probably the belt. But if you can isolate a pully with the motor off and put a tiny water behind one without getting it on the belt, and do each one like this, that would be good because you will figure out exactly what is making the sound. My guess is a new belt, but then again some people do have a pully that does sound like that. Like the guy above me, mine was the belt. I am due for a new one but since washing my motor and doing the belt trick mine has been okay. If I go mob in the dust it comes back though.

 

Judging from offroading and splashing you have mud and dust on the belt or pulleys, give it a good spray down with a hose and then run it see if that helps. It takes one tiny piece of something to create a whole lot of noise with the belt

 

someone drive hard and no tell

 

Thank you everybody for the input. I am always driving it in dusty conditions and that water bombing today was in chocolate milk water too.

Possibly just some dirty components. I feel I have the ability to replace the belt myself, as I am capable enough to lift my truck and do an alignment myself. But should I just take it to the dealership under my 3/36 standard warranty? Will a serp belt be covered? Sorry for my ignorance.

 

I bought a new belt and installed it. No more noise! Thank you everybody.

 

Get yourself a spray can of belt conditioner from walmart or your local auto store and spray away.