Can anyone identify this?

So last year we were headed to North Carolina before Christmas. This sound was just starting, so I thought tensioner, idler and serpentine would fix it, it didn't. Fast forward to 10k miles later, and it's still there. Before I have a break down, does this sound familiar to anyone? I thought I saw something before about it being the alternator? Or possibly water pump?

https://youtube.com/shorts/6izbO2RCfJc?si=GMC4zBrhA5sQrTZI

 

My alternator needs to be replaced per Toyota and it’s a different sound than that if that helps. You may want to remove the serpentine belt and spin each pulley by hand just to test. Alternatively get a mechanics stethoscope for 10$ to identify too.

 

You know what's kind of funny, I never looked into the cost of those Didn't realize they were so cheap. And you have a point, shouldn't have assumed before I did the belt and pulleys before, and checked the other components at that time. Thank you

 

As @Ponderosa_Pine suggested the stethoscope helps. Be careful as sometimes checking under load (running) will reveal a pulley that has an issue.

 

I more worried about getting the stethoscope ripped off my head Serpentine, idler and tensioner were new a year ago. Didn't make a difference to the noise

 

Interesting. My 17 has had a similar noise but mine only shows up when it’s cold out and is not that rythmic. As soon as the motor is good and warmed up, the sound disappears. Convinced it was the alternator, I changed it. Still there. I’m not into swapping parts unless I’m convinced I found the problem. I recently discovered though, after the noise starts, if I put the truck in gear, the noise stops. It has a very similar whine like yours. Normally, I’d be looking at power steering but even with 35’s on the truck, I can crank the wheel lock to lock and no change in pitch.

 

an alternative to a stethoscope is a long screw driver or pry tool. Put the end against suspect noise generators and the handle against your forehead or jaw…you’ll be able to feel it as you close in and find it.

 

Alternator noise is really deceiving because they have brushes and a commutator along with bearings.

 

Originally it was only when it was cold, and the truck was cold. Now it seems to be longer lived during those times, but doesn't completely disappear. My doesn't stop when put in gear. I've also cranked my wheel cold, and don't notice a change in volume or rhythm.

 

Oh great, my clumsy ass holding a screwdriver by spinning parts against my jaw or forehead. That could only end one way

 

Don't do that at wide open throttle, lol. Was hammering my truck one day and blew the seals in the PS pump.

 

And if it's not an obvious accessory you can run it for a couple seconds without the belt to see if it's internal noise. This is how I diagnosed a chain tensioner on a Saturn

 

Exactly!

 

Unlikely a lesson you'll learn twice though. It's actually a pretty safe process. If you get too close something your tool will get knocked out of your hand before your head gets close to the handle. I'm a bit gifted at injuring myself as well, and haven't damaged myself doing this yet.

 

A new alternator for your 2021? What caused them to come to that conclusion?

 

Took it in for an oil change and it was making a noise. I had previously replaced the idlers/tension so intentionally let them figure it out without suggesting. I am not sure how they came to the alternator conclusion other than “diagnostics”. Getting it done tomorrow and should be covered under a 100k warranty, will know more soon.

 

https://www.tundras.com/threads/2016-toyota-tundra-whining-noise.87725/

This is the thread that led me to the alternator. Although there is no video to support my thoughts. I might look into rebuilding it and see if it changes.

 

To update anyone in the future, it was the alternator. I was going to rebuild it, but abandoned that when it was getting close to closing time at Napa. Everything felt good, so in the end I don't know where the noise was coming from, but glad it's resolved.

 

You are the fourth person (including me) that I know who has had a 2020+ alternator fail. Starting to feel like they may have had a bad batch of internal components for our years.

 

Definitely possible. Toyota ended up replacing it, I didn’t feel like it was failing, the volts were normal range. My battery was getting old too and replaced that. I thought it was more the bearings were bad. But then turns out when I picked up the keys they said the replacement didn’t fix the sound the truck had lol. They wanted to remove my supercharger and rebuild it (third party). I went home, bought a stethoscope, realized it was an idler pulley making the sound, replaced all three pulleys under an hour and sound was gone!