My guess based upon prior experience is that the alternator is the cause, especially if you didn't hear the whine when the alternator wasn't being run.

 

Well, if it is the alternator, I don't suppose it'd be worth it to simply change out the bearings, would it? I ask because this alternator may be a little bear to get into.

 

If the alternator is the cause I would look into getting a new or rebuilt alternator. The problem more likely is in electrical generating parts and circuitry rather than in the bearings. Disassembling an alternator is a possibility but it may be difficult to get the proper replacement parts. Meanwhile the vehicle is down. Sometimes whine is a warning of impending failure, at other times it can carry on for quite some time.

Other forum members may have different insights. . .

 

I would loosen the belt, and see if you can feel which pulley does not seem smooth. That may tell you where the bearing problem is.

Some people will inject grease into the bearing of an idler pulley to get more time out of it. You can search for a grease injection needle made to be pumped by a grease gun, or maybe you have a suitable syringe with needle.

 

It's the idler pulley.

Well, after looking around to see if I could replace only the tensioner idler pulley, I found both the Dayco 89158 and Gates 36173. Unfortunately, these appear to be only for the 2006-2009 Rav4. Rats. Guess I'll have to go about replacing the whole kit-n-kaboodle.

I pulled this from a ToyotaNation thread in case anyone is curious:

I had to remove the dust cover underneath the engine. The old tensioner had to be removed in pieces, because of lack of clearance to extract whole. The new tensioner had to be dismantled and installed in pieces. The key thing to note is: If you do not plan on removing the main pulley off of the crankshaft and the water pump pulley, plan on having some assistance on hand to pry motor over at the motor mount. Without using a prybar, I would have not been able to get the parts out. I hope someone can be helped by my experience.
Tools:
10mm socket and box/end wrench to remove dust cover under engine
14mm socket and box/end wrench to remove bracket bolts on tensioner
16mm socket and box/end wrench to remove spring on tensioner
19mm socket and box/end wrench to relieve tensioner (belt removal/install)
large prybar to move motor over enough to remove and install parts

I may go about removing the crank pulley. As far as SST tools go, try this out:

http://toyota.spx.com/PDF/ToyotaMasterindex2005.pdf

 

Do you really have to remove the crank pulley to change the accessory drive idler or are you talking about the timing belt tensioner pulley? If it's not absolutely necessary, I would avoid removing the crank pulley at almost all costs. These can be a bear to break loose (~200ft.lb.) and if you aren't real careful it's possible to mess up the valve timing with potentially very expensive consequences.

If you are talking about replacing the timing belt idler/tensioner pulley then of course you will have no choice but to remove the crank pulley as well.

 

It's this little #$($#%$

This doesn't look to be an easy job. Yee haw.

Also, as far as the procedue mentioned states, one should "pry motor over at the motor mount". The passenger side mount only allows the engine to travel up / down, not left / right. Or am I missing something?

 

With the right tools to remove the crank pulley, and you do need to remove the crank pulley, this is a one hour job. Torque spec is 125 ft-lb, meaning that you'll need considerably more than that to break it loose. I'm all for DIY, but, man, I hate jobs like this. Shop around at a dealer or an indy shop and see what kind of price you can get, but I would guess $250-$300.

 

I got myself a $7 set of pry bars from Harbor Freight this morning just to see how much the engine could be pried. I wouldn't buy life-critical items from HF (air compressor, jack stands, etc...), but a plain Jane piece of steel is worth the cheapness. Anywho, with the 24" bar, I got roughly 1/8" of wiggle to the driver's side. Hmmm...

I've thought about, but haven't tried, unbolting the passenger side motor mount with the engine supported from beneath with a jack and jack stands. That would remove some of the rigidity in the system and could possibly get a little more travel.

I'd like to avoid a $500 job for a stupid idler if possible.

 

Well, here's the update for future reference in case anyone needs it. The tensioner idler pulley's bearing is completely shot. I wussed out and let the local garage change it for me. It's the wife's baby hauler after all, and I'd hate to spend a day or more cussing it in the driveway only to be stuck unable to get the new one on.

The tensioner (Gates P/N 38216) in the picture above from Amazon: $98 (had a $50 gift card, so I only paid $48 :mrgreen: )
Labor to replace: $104

In total, I actually spent $152 on the fix. Well worth the money as the Rav is dead silent now, the wife is happy, and I didn't spend all day cussing. I kept the old tensioner and plan to tear the bearing down to look at the damage. It still moves "freely" so I don't expect much carnage, but we'll see.

 

Congrats and well done! In my book also, its well worth $152 to avoid all of the hassle of doing the job yourself and experiencing the consequences. Along with avoiding the time and cussing factors, if it were I there very likely would have been the added expenses for bandages and maybe even a trip to the ER! :thumbs_up: