It may be the belt is just a little loose and squealing while the alternator is recharging the battery for the starting discharge. That's pretty common on many vehicles.
My trick is to spray some water on the belt. If the squeal stops for a few seconds it's loose and not a bad tensioner.

 

It may be the belt is just a little loose and squealing while the alternator is recharging the battery for the starting discharge. That's pretty common on many vehicles.
My trick is to spray some water on the belt. If the squeal stops for a few seconds it's loose and not a bad tensioned.

I was advised many years ago to put some plain talcum powder on the belt. This shuts it up and will last a bit longer until you get around to adjusting it. If not too soon you may have to repeat it daily!!

 

The original poster said he heard a squeal for a couple of seconds AFTER THE ENGINE HAD SHUT OFF. And only when the engine is cold. I don't think water or talcum powder on the belt is the answer.

 

After the
engine is started & before it gets hot ....
There is a squeal for a second or two after the engine is shut off.

Somewhat confusing for sure! :doh:
I don't know how anything could squeal after the engine stops and it must do that within half a second after shutting the key off unless he means from revved up.

 

The squeal happens after the engine is shut off. I start the engine up let it idle for a few seconds (not revving it up) & then shut it off. When I was checking the bearings with the stethoscope the engine was hot so I'm going to give it a try again with a cold engine.

 

The squeal happens after the engine is shut off. I start the engine up let it idle for a few seconds (not revving it up) & then shut it off.

Wow, that's a new one on me!

 

I suspect a failed Overrunning Alternator Pulley. Overrunning alternator pulley - Wikipedia, the free encyclopedia That is a one-way device on the shaft of the alternator.

http://www.decouplerpulley.com/files/RotoRxbrochure.pdf says

The Overrunning Alternator Pulley (One-Way Clutch) has a simple one-way clutch inside the pulley. This internal clutch allows the rotor of the alternator to coast to a stop when the engine is shut down. This “overrunning” feature eliminates “chirp” sounds that occur when the engine decelerates quickly, causing the belt to slip (engine shut down or transmission shifting).

 

I suspect a failed Overrunning Alternator Pulley.

Makes sense. It can't think what else it could be. But since the primary reason for the special pulley is during shifts why wouldn't he hear squeal then?

 

Overrunning alternator pulley. That's a new one on me. Can it be replaced without having to replace the entire alternator?

 

I have only read about them, but with the right tools it appears to be replaceable. You will want to do more research, because I have never been involved in troubleshooting or replacing one.

The Gates part number would seem to be 37026P but again, do your own checking. More Information for GATES 37026P

http://www.gates.com/common/downloads/files/australia/brochure/ADP_brochure.pdf

http://www.gates.com/oreilly/tech_tips/Gates Alternator Tester ADP Hang Tag.pdf

It would appear that a special tool is needed.

 

Perhaps we should watch the alternator with the engine running and get wife to switch the engine off and see if the alternator runs on???
Must admit this is a new one on me as well but would the manufacturer bother with such a feature - unless it's on a Lamborgini!!!! :shrug:

 

I checked it again yesterday. The squeal comes from further back somewhere in the tensioner area. I also watched the alternator pulley as my wife shut the motor off & pulley stopped when the motor stopped. I also had my mechanical stethoscope on the center of the tensioner pulley as she shut off the motor & it sounded to me like it might be the problem( bearing spinning on shaft???). I'm taking it to a shop on Wednesday to have them fix it(It's out of warranty). I thought I would try it myself but it looked like it might involve too much profanity on my part

 

Well it turns out that it was the Overrunning Alternator Pulley. Cost me $566 for a rebuilt Nippondenso alternator (Apparently new ones aren't being made anymore) plus $323 for labor. Our limited requires the 150amp alt. as per the vin number.
I don't have a warm & fuzzy feeling about this car anymore. $900+ bucks to fix the alternator & a while back I took it in to the local Toyota dealer to have them check out the clunky steering. They couldn't duplicate it so I replaced the steering linkage myself. No more clunking. Not very good reliability on a vehicle with less than 30,000 miles

 

Oh boy, I feel bad about this. I just checked at the Advance Auto Parts web site, and they show an aftermarket overrunning alternator pulley for $69.95: :wall

Buy Litens Overrunning Alternator Decoupling (OAD) Pulley - Original Equipment Quality 920954A at Advance Auto Parts

Litens Automotive® is the original equipment supplier to Toyota for this decoupling alternator pulley. This replacement pulley is also designed and produced by Litens© and is exact in all form, fit, and performance characteristics as the original equipment part (with the exception of not having the car manufacturer's logo or part number applied to the part). Decoupling pulleys are engine specific and should never be interchanged with other types of pulley technology. The Litens® OAD type pulley is designed to free-wheel in one direction and, with an internal spring and damping device, softly engage in the opposite direction. The OAD is designed as a sacrificial part of the front-end accessory drive system, protecting other belt driven component as well as the alternator. The correct decoupler pulley ensures smooth, quiet performance as well as increasing vehicle gas mileage. Under normal driving conditions, the original pulley will require replacement in approx. 100,000 - 120,000 miles.

They mention you need a Miller Special Tool® P/N 8433A as well as a torque wrench to replace it. And Advance sells the remanufactured Denso tow-package alternator for $758!!

 

Good find Junebug ! Most garages would try to tell you everything is toast!

Just wait till the poster sees this !

 

SPX Miller Special Tools , 8433A De-Coupler Pulley Remover/Installer

Miller Tool 8433A REMOVER/INSTALLER, DECOUPLER

I see no current Ebay listings, but there are several completed listings. The ones I saw all sold, so it looks like somebody who bought one could probably get over half of the money back by reselling it. It would be even better if the auto parts store had one as one of the tools they lend.

 

Hey I just had this. Took the plastic cap off the pulley. Found rust. Cleaned with brake clean on a rag and a couple drops of oil on the end. Twisted with hex bit socket one way until it turned one way with slight drag and felt springy the other way. The noise went away! I figure it needs replaced but at least I’m sure what it was. Parts and tools easy to find online now. Gates made a training video on YouTube also.

 

Hey I just had this. Took the plastic cap off the pulley. Found rust. Cleaned with brake clean on a rag and a couple drops of oil on the end. Twisted with hex bit socket one way until it turned one way with slight drag and felt springy the other way. The noise went away! I figure it needs replaced but at least I’m sure what it was. Parts and tools easy to find online now. Gates made a training video on YouTube also. 2008 RAV 94K miles. V6 w/tow package