Serp Belt Squeeling constantly now '03 V6

blackmax

blackmax

New member
Serp Belt Squealing constantly now '03 V6

So, I know this is an "issue" with the V6 models. Usually it's just a non-seated belt or something with the alignment of one of the idlers or maybe the tensioner. However, it's usually a 1-5 minute thing, until the engine gets warm. I've experienced those probs in the past, and they eventually just went away. Unfortunately, now mine is now doing it at all times (just started yesterday). I can drive for 40 miles, and sure enough, at idle, it's squalling pretty badly, non-stop.

So, while it COULD be a bad idler bearing or other rotating accessory, I'll try the serp belt first (this one has 60k miles on it anyway). Now, I'm pretty mechanically inclined, and have about every tool known....however, I have never replaced a serpentine belt. I do know where the tensioner pully is. My question is this- how difficult is the serp to replace? No bid deal or do you need like 7 hands, plus a trained chimp to help, in addition to special tools?

Thanks.
 
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I had mine done at the dealer for $85 (parts and labor). I'd rather spend $85 than breaking something that might cost me more.
 
I replaced mine in about ten minutes.Breaker bar and socket.Place the socket on the tensioner,pull it back far enough to get the belt off,work it around the fan.Do the same in reverse for the new belt.I purchased mine from O'Rielly Auto parts far about $35 bucks.If you think it might be something else,put a few drops of liquid soap on the belt while the engine is running,if the noise stops,it's the belt,if not,it's a bearing.
 
imdav2u said:
I replaced mine in about ten minutes.Breaker bar and socket.Place the socket on the tensioner,pull it back far enough to get the belt off,work it around the fan.Do the same in reverse for the new belt.I purchased mine from O'Rielly Auto parts far about $35 bucks.If you think it might be something else,put a few drops of liquid soap on the belt while the engine is running,if the noise stops,it's the belt,if not,it's a bearing.
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Oh, I see now. The tensioner pulley sort of "cocks" back and is spring loaded. Ok, always wondered how that worked. So the trick is keeping the tension off, while removing the old and installing the new. I think there's a hole that allows the pulley to be held in the open position. Ok, cool.

Yea, I'll drop some soap on this am to see if it stops it or not.

Wonder how long the rotating accessories last on the V6? I have 102k miles and wonder about the water pump and alternator.......hate to get stuck whoknowswhere and whoknowswhen.
 
ah jeez, so I put some soap on the belt and the squealing increased. I then tried a little WD40, it quieted for about 1/2 second, then came right back. It's LOUD and constant. So, I'm guessing I've got a bearing going bad. It seems (but who can really tell) to be coming from the driver's side of the engine. So, I'm guessing the candidates are: idler, auto tensioner, alternator.....or even the water pump starting to freeze up? I think that what I'm hearing is in fact the belt (as opposed to a bearing), since it sounds just like you'd expect a slipping belt to sound, but maybe a bearing is freezing up and causing the belt to slip on THAT pulley. Well, I have time on my hands, and can't stand to take it to a shop, where I know they will fix something which in my experience is rarely if ever the real problem. After 3 visits and $1500, they might find it.


Well, I guess I need to pull the belt off and see what I can find. I wonder if I'll be able to diagnose a bad bearing just by spinning it by hand? :confused: It's a place to start. I can always drive the squealing thing over to my mechanic if I come to a complete dead-end.
 
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blackmax said:
ah jeez, so I put some soap on the belt and the squealing increased. I then tried a little WD40, it quieted for about 1/2 second, then came right back. It's LOUD and constant. So, I'm guessing I've got a bearing going bad. It seems (but who can really tell) to be coming from the driver's side of the engine. So, I'm guessing the candidates are: idler, auto tensioner, alternator.....or even the water pump starting to freeze up? I think that what I'm hearing is in fact the belt (as opposed to a bearing), since it sounds just like you'd expect a slipping belt to sound, but maybe a bearing is freezing up and causing the belt to slip on THAT pulley. Well, I have time on my hands, and can't stand to take it to a shop, where I know they will fix something which in my experience is rarely if ever the real problem. After 3 visits and $1500, they might find it.


Well, I guess I need to pull the belt off and see what I can find. I wonder if I'll be able to diagnose a bad bearing just by spinning it by hand? :confused: It's a place to start. I can always drive the squealing thing over to my mechanic if I come to a complete dead-end.
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There are three idler pulleys plus the tensioner pulley that are candidates for the noise which could be a bearing failure. I would suspect one of them, before one of the driven accessories (alternator, power steering pump, water pump, or A/C compressor). I have replaced all four on mine in the last 8 months. It is very difficult to pin down which one might me making the noise without first removing the belt. But once the belt is removed, you should be able to feel the bad one fairly easily. I don't know the part numbers at the moment, but NAPA carries them.
 
Jed said:
Really? I've never heard that the V6 has any such issue. I think it is extremely rare from what I've seen.
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squealing belts? extremely rare on v6? That's like saying sand is extremely rare at the beach. Seriously, it's very very very common.
 
TechWrench said:
There are three idler pulleys plus the tensioner pulley that are candidates for the noise which could be a bearing failure. I would suspect one of them, before one of the driven accessories (alternator, power steering pump, water pump, or A/C compressor). I have replaced all four on mine in the last 8 months. It is very difficult to pin down which one might me making the noise without first removing the belt. But once the belt is removed, you should be able to feel the bad one fairly easily. I don't know the part numbers at the moment, but NAPA carries them.
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Sounds good. I got the new belt this afternoon, and may pull the old one off this evening. I hope it's not the tensioner, but will soon know.
 
blackmax said:
squealing belts? extremely rare on v6? That's like saying sand is extremely rare at the beach. Seriously, it's very very very common.
Click to expand...


If that were true, then I'd see a bunch of threads with a bunch of V6 owners complaining about it. So far I've only seen this thread. Where do you get your info?
 
Jed said:
If that were true, then I'd see a bunch of threads with a bunch of V6 owners complaining about it. So far I've only seen this thread. Where do you get your info?
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Toyota service bulletins and many, many, many people with a V6 toyota (not just 4runner)

Here's something from a search (there are thousands)
<<<<<<<<<<<<<

Guys,

As a favor for my friend, i researched his problem that he is having with his 2003 4th gen V6. his belts are squealing like pigs and the dealership (Longo) was not able to fix it after two tries. Of note, one of the service writers blamed it on the cold, east coast climate's effect on his vehicle

fire that fool already.

Anyways, there is a TSB on it and it is TSB EG012-03. One of the best descriptions of the problem came from a T4R member and he had this to say:

There is a TSB on this problem with the V6. I had the same problem with mine, and it took 5 trips to dealer before they found the TSB and ordered the parts to 'fix' it. It started after about 4K. Basicaly, the problem is with improper alignment of the tensioner pulley for the belt. Because the tensioner pulley is offset from the crank and fan pulleys, the belt has to shift over as it transitions from one to the other and back again. What you are hearing is the belt rubbing against the tensioner pulley as it goes around it. For a short term 'fix' try spraying a belt dressing on the back side of the belt as it is running, the noise will go away almost instantly. But it will come back after a while. The TSB calls for the dealer to install a new tensioner pulley, and a new mounting bolt along with a shim, and a new belt. They did mine in July, and it was OK until early in December, when I think I noticed it again. But now that it has gotten really cold it has gone away again. I will wait until it warms up to see if it returns again. I don't recall the number of the TSB right now, but if you check the NTSB site, they have it listed.

As for further reading and reference, check out these threads:

http://www.yotatech.com/showthread.p...erpentine+belt
post #6 and #8
http://www.toyota-4runner.org/showth...ght=noisy+belt
http://www.toyota-4runner.org/showth...p?threadid=353
http://www.toyota-4runner.org/showth...p?threadid=452
http://www.toyota-4runner.org/showth...belt+tensioner

I think the best course of action would be to call Toyota USA with your VIN and see if your vehicle falls under the VIN range for this fix. If the answer is yes, I would make a call to your local Toy dealership and let them know taht you are aware of TSB EG012-03 and that you've called Toyota USA and verified that you fall under the VIN range and qualify for the service.
 
Okay, that's good info. But you should realize that the TSB in 2003 was more than likely implemented on all 4th gen 4Runners from 2004 thru 2009. That's probably why virtually nobody on this forum complains about it.

BTW, I was going to mentioned pulley alignment, as it is one of the main causes for belt noise.
 
Jed said:
Okay, that's good info. But you should realize that the TSB in 2003 was more than likely implemented on all 4th gen 4Runners from 2004 thru 2009. That's probably why virtually nobody on this forum complains about it.

BTW, I was going to mentioned pulley alignment, as it is one of the main causes for belt noise.
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Yea, I puled the old belt off last evening. Between conference calls today, I'll check all the rotating stuff to see if something's going bad. I've had this problem before (twice) and the mechanic replaced an idler, which was still good. SO, I have one "spare" idler, if that turns out to be the issue.

It could just be an old belt plus slightly out of alignment like you said. The new belt I purchased is a "gatorback", which may very well eliminate any slippage due to slight misallignment. I'm betting the new belt fixes the problem.
 
I put one of those "gatorback" belts on my 4Runner, but I didn't like the sound it made, so I took it off and returned it. If the one you got is like mine, it doesn't have the same groove pattern as the OEM belt. If so, you'll probably notice the difference in sound right away.
 
Jed said:
I put one of those "gatorback" belts on my 4Runner, but I didn't like the sound it made, so I took it off and returned it. If the one you got is like mine, it doesn't have the same groove pattern as the OEM belt. If so, you'll probably notice the difference in sound right away.
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ALL RIGHT! So, I checked all the idlers. The one on the bottom (which is a double bearing?) didn't spin freely so I removed. Well, I think it's just a bit stickier due to the double bearing, so I put it back on. All the idlers and tensioner had the same amount of "play" in the pulley (1/64" or maybe less?). I guessed that since they were all the same, and they all turned freely, that was fine. So, I put the new belt on.

Gotta say, putting a new belt on, with the fan in place, is kinda tough, and takes some determination. Finally got it in place. Noticed the trick to finishing it is to ratchet the tensioner by hand about 1/4 turn, THEN put the breaker bar on the ratchet and uncock all the way. The reason for this is that with the breaker on the ratchet, you will hit the fan clutch before the tensioner is fully retracted, thus you probably won't get the belt on. Anyway, I finished it.

Fired it up, and it's quiet as a church mouse......now for a test drive. This is where I find out that left out some mundane detail...that causes a problem. :redbrick: The Gotorback sounds fine to me; but, I don't really care so long as it's not chattering or squealing.
 
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+1. Mine was squeeling pretty bad on startup around 45k, now 70k. Changed over to a gatorback and have been happy. I don't notice a difference in sound. Took me like an hour to do it cause I was pulling back the tentioner with a small ratchet and that took a ton of strength one handed, while the other works magic with the belt. Glad it wasn't anything more serious.
 
Guys, I too have the serious squeak/chirping emanating from one of the bearings or?. Its really, really hard to isolate the exact source. My problem doesn't seem to be the belt but a bad bearing on one of the accessories.

I've tried to narrow it down by spraying lube onto the specific items (alternator, ac, wp etc.) but the lube gets spread across the belt and gets distributed to all the bearings...and I cant find which one it is.

Any suggestions short of taking off the serpentine belt and checking each bearing by hand? At 105k I am probably due for a new WP and or a Alt. but would rather not replace them all.

The sound is far more noticeable when I start up but seems to come and go while I drive. Its not constant which is the frustration, people now know its me coming down the street making that chirp, chirp chirp sound. Kind of removes the stealthness

03' Ltd 2wd V6
 
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