Continuous Squeal from Serpentine Belt

I would check the Idler Pulleys to see if one of them has possibly failed. If one of them is not turning due to a failure, it would cause a squeal. No matter what the cause, it needs to be addressed immediately before the belt fails.

 

While I agree; constant noise doesn’t seem like a loose belt. But it would be the first thing I check.

 

As far as checking, am I just doing a visual inspection to ensure they are turning?

 

To start with, yes.

 

Ok, will do so in the morning . thanks for the help thus far

 

I went thru a similar issue that involved the tensioner and 2 pulleys on the drivers side. Truck was a 2015 V6 and had less than 36K miles; less than 3 yrs. old.
During the 3rd visit for my problem the dealer told me they needed to bring in a Toyota Field Technical Specialist. They had mistakenly replaced a part that was not faulty. 2 weeks passed and no communication from dealer. Called them back. "Oh...we will try and reach out to so and so again". Another week went by. I called Toyota Customer Service number - opened a ticket. Dealer calls next day and tells me the tech spec. was coming in. Right...
They needed a specialist to determine a belt tensioner and 2 pulleys were bad? No wonder you can't get anything fixed at dealerships.

 

The easiest way to get in there IMO, is to take off the skid plate. From underneath, you can put a breaker bar or ratchet on the tensioner pulley. Take tension off the belt (the direction will be obvious) and slip the belt off the tensioner. This will allow you to turn the idler pulleys by hand. If they're turning fine (tensioner pulley too), the the problem is in one of the component pulleys - water pump, alternator, fan, etc. Most of those won't turn by hand.

The alternator wouldn't be charging the battery, so that's out. If it was the water pump, your engine would've over heated in minutes. It's not that. Look and see if the fan turns, could be a bad clutch. Does the air conditioning work? Could be that. The starter obviously works, so it's not that.

I'm thinking you'll discover a bad idler.

 

Thanks for all the info. Literally, the next morning after I initially started this thread, I started the truck up and drove it, without any noise whatsoever. I drove it probably 10-15 miles yesterday without any sort of sound. I took it to the dealer for an oil change and had them inspect it, they didn't advise any issues....

So...as of now, there is no squealing or noise coming from the belt...

 

Though you may not have the bumper to bumper warranty anymore, you still have the powertrain warranty, which is up to 5 years, 60,000 miles, I believe. Since this is an issue with the belt's tensioner, take it into the dealership to try to get it replaced under warranty, as it may be covered. I personally would just change the belt and the pulley myself, but it's not my truck. Good luck OP.

 

SOLVED!!! Check your belt routing. Turns out, it is possible to route the belt in such a way that it seems tight and the truck runs fine but in fact the tensioner is bottomed out and therefor not providing adequate tension. I wasted a lot of time and money before I figured out this stupid mistake