Horrible Serpentine Belt Squeal
04-09-2013, 10:43 PM
#21
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I'm going to have to deal with this issue again myself. It happened for the first time about 18 months ago, but it would only chirp after the engine was fully warmed up, and would continue at any rpm. The culprit ended up being the main tensioner pulley; replacing that took care of the problem for over a year.
Then late this winter it developed a new belt chirp, but this time the parameters are different - now it only chirps at idle, and only when the engine is cold/still warming up. It's not that bad yet, so I haven't taken the time to see which belt system it's coming from. I have never replaced the A/C tensioner or idler pullies, so I'm hoping one of those will be the cause this time around.
Then late this winter it developed a new belt chirp, but this time the parameters are different - now it only chirps at idle, and only when the engine is cold/still warming up. It's not that bad yet, so I haven't taken the time to see which belt system it's coming from. I have never replaced the A/C tensioner or idler pullies, so I'm hoping one of those will be the cause this time around.
04-09-2013, 11:17 PM
#22
Yeah, I think it's just an ongoing problem. I took care of a few of those I hope by replacing the idler and tensioner. The Power Bastards alternator seems to have been the main culprit. I'm going to contact them to see what they can do about it. Maybe send it back for them to check it out. When you free spin it by hand you can hear the nylon bearing (or whatever) and it sounds pretty bad. Which is unfortunate since I've only had it on the car a few months and have maybe put 500 miles on the car since I installed it.
The good news is, my voltage drop seems to be fixed. The PB had an OD pulley which caused a 14.2-14.7 V charge at idle before dropping back to 12.7 once the battery was charged. But it'd drop into the low 11s at idle under a load, because my RPMs were too low ~600. Blipping the throttle back up to 700+ and it'd jump back to 12.7~13.1. I'm hopeful the stereo I'm wanting to install doesn't bring the stock Alt to its knees... But I don't need a $300 alt that doesn't work and squeals like crazy in there either.
The good news is, my voltage drop seems to be fixed. The PB had an OD pulley which caused a 14.2-14.7 V charge at idle before dropping back to 12.7 once the battery was charged. But it'd drop into the low 11s at idle under a load, because my RPMs were too low ~600. Blipping the throttle back up to 700+ and it'd jump back to 12.7~13.1. I'm hopeful the stereo I'm wanting to install doesn't bring the stock Alt to its knees... But I don't need a $300 alt that doesn't work and squeals like crazy in there either.
04-12-2013, 01:55 PM
#23
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Does ANYONE know of any high quality pullies, made here, with U.S. (or Canadian) sourced/made bearings?!?!
The Sino made bearings seem to be the source of all of the problems with noise/longevity that everyone is having recently.
I would GLADLY pay more for quality pullies to not have to be changing these things out every few months or so.
The Sino made bearings seem to be the source of all of the problems with noise/longevity that everyone is having recently.
I would GLADLY pay more for quality pullies to not have to be changing these things out every few months or so.
04-12-2013, 02:24 PM
#24
No idea. But the bearings on the stuff I bought were SKF.
I swapped the stock Alternator back in there. The noise is almost totally gone. Now it's a light chirp as the RPMs climb. I think the PS Pump is the culprit for that. But the banshee raping the chalk board sound was the Power Bastards Alt. I'm going to see what they tell me.
I swapped the stock Alternator back in there. The noise is almost totally gone. Now it's a light chirp as the RPMs climb. I think the PS Pump is the culprit for that. But the banshee raping the chalk board sound was the Power Bastards Alt. I'm going to see what they tell me.
04-12-2013, 06:41 PM
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Does ANYONE know of any high quality pullies, made here, with U.S. (or Canadian) sourced/made bearings?!?!
The Sino made bearings seem to be the source of all of the problems with noise/longevity that everyone is having recently.
I would GLADLY pay more for quality pullies to not have to be changing these things out every few months or so.
The Sino made bearings seem to be the source of all of the problems with noise/longevity that everyone is having recently.
I would GLADLY pay more for quality pullies to not have to be changing these things out every few months or so.
04-12-2013, 07:36 PM
#26
If you order tensioner/idler pullies from GM, what you get will be stamped as "made in Canada", though I don't know if that also means that the bearings are sourced from Canada or elsewhere. The assembled pullies do look identical to what was originally issued by the factory though.
04-13-2013, 11:24 AM
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go to gm and put a stock gm pully on the aftermarket alternator. those aftermarket alternators i think put out more amps, therefore cause a heavy load on the engine vs the stock gm alternator. loading up the alternator puts a LOT of stress on the engine belt. kinda like when you turn everything on your car on all at once at and your cars idle drops a little. plus those aftermarket alternators have pullies and bearings from god knows where. If i was gonna by an aftermarket alternator i would imagine id find one that doesnt involve changing the speed the alternator spins, but rather slightly better internals to boost amps, but not voltage.....
and my car now makes noise, but its the stupid idler pully. i had belt squeal MAJOR when i got the car and found out the alternator was under such a heavy load due to a nutso aftermarket amp with corred cables the previous owner added. minute i turned on the car.... SQUEAL. then i accidently unplugged the amp one day and the squeal vanished, plus the idle jumped up a little. never woulda figured that.
just noticed in your sig you got an ATI underdriven pully...can you say alternator overload? so your using a higher output alternator that is now spinning slower that the stock one. betcha thats some of the problem for the squeal. id throw an ammeter on there and see how hard that alternator is working under load when its cold and the battery is being charged after the car sits.
and my car now makes noise, but its the stupid idler pully. i had belt squeal MAJOR when i got the car and found out the alternator was under such a heavy load due to a nutso aftermarket amp with corred cables the previous owner added. minute i turned on the car.... SQUEAL. then i accidently unplugged the amp one day and the squeal vanished, plus the idle jumped up a little. never woulda figured that.
just noticed in your sig you got an ATI underdriven pully...can you say alternator overload? so your using a higher output alternator that is now spinning slower that the stock one. betcha thats some of the problem for the squeal. id throw an ammeter on there and see how hard that alternator is working under load when its cold and the battery is being charged after the car sits.
Last edited by DaytonaBlues; 04-13-2013 at 11:45 AM.
04-13-2013, 01:34 PM
#29
Chirping of the FEAD as demonstrated in your video (classic BELT noise) is NOT caused by pullies, minor alignment issues, or pulley bearings. It's dirt, period. It's either built up on the belt contact area of a pulley or embedded into the belt itself. Most likely it's compressed into/onto the grooved surface of the belt.
You can recondition a dirty belt by removing it and scrubbing it with a bristle brush soaked with soap and water. Or you can lightly sand the belt with sandpaper with the engine idling (use extreme caution here!!!!).
You can recondition a dirty belt by removing it and scrubbing it with a bristle brush soaked with soap and water. Or you can lightly sand the belt with sandpaper with the engine idling (use extreme caution here!!!!).
04-13-2013, 01:37 PM
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Just noticed in your sig you got an ATI underdriven pully...can you say alternator overload? so your using a higher output alternator that is now spinning slower that the stock one. betcha thats some of the problem for the squeal. id throw an ammeter on there and see how hard that alternator is working under load when its cold and the battery is being charged after the car sits.
^^^You just may be onto something here!
This is also part of the reason I am going to a STOCK sized Fluidampr balancer/crank pulley to replace my destroyed ASP 25% UD garbage, even though I only have a stock Delphi alternator on the car.
04-14-2013, 08:38 AM
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I hear ya man. I've had so many friends who went with UD pullies only to end up with horrible belt noise or worse. I don't think that anyone should necessarily need underdrive pullies unless u are strictly strip use only. That's just been my experience. UD pullies are probably ok for a non heavy stressed alternator application (like drag cars with ls1 swaps), but you change that speed the alternator is spinning the the alternator is thinking that the rpms are lower thus the harder it has to work to keep up with the huge amp and voltage demands our cars have. Alternator under heavy load but slower pully rpm=belt slipping=heat=squeaking
04-14-2013, 11:34 AM
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In terms of a root cause, I would agree. However, an increase in alternator load can certainly be the trigger point which exposes belt (slip) noise that is due to a belt being old/worn or loose.
Last edited by RPM WS6; 04-14-2013 at 11:40 AM.
04-14-2013, 12:47 PM
#35
The ATI is sitting in my office with a bunch of other parts. I'm going to swap them all at the same time. Which is why I wasn't going to spend a ton on replacing belts and such when they'll just get replaced again in a couple of weeks...
04-15-2013, 01:19 PM
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I hear ya man. I've had so many friends who went with UD pullies only to end up with horrible belt noise or worse. I don't think that anyone should necessarily need underdrive pullies unless u are strictly strip use only. That's just been my experience. UD pullies are probably ok for a non heavy stressed alternator application (like drag cars with ls1 swaps), but you change that speed the alternator is spinning the the alternator is thinking that the rpms are lower thus the harder it has to work to keep up with the huge amp and voltage demands our cars have. Alternator under heavy load but slower pully rpm=belt slipping=heat=squeaking
I also always wondered if the lower output from them (especially in tandem with an UD alternator pulley) resulted in a lower spark voltage output to the plugs??
04-25-2013, 11:17 PM
#38
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So, I've had this problem for a while, but I just ignored it (as much as I can), because I'm about to do a full top-end rebuild on the car and don't want to rip into it just yet.
But the problem is, I just can't stand it anymore! Car is all stock right now with a Power Bastards Alternator. Engine has 144k miles on it.
When I put the alternator on, it chirped a little, so I got a 1" shorter belt, and it didn't chirp. Everything was fine. Then one day it decided to start chirping like crazy. It hasn't stopped since then. I put the old belt back on, since it actually seemed to help (won't chirp when warm at idle with the factory length belt).
I put a new tensioner as well, thinking maybe there was still belt slip. Nada.
I've tried to chase down the sound, but it's so incredibly loud and overwhelming, I can't tell where it's coming from. I took the accessory serpentine off and it goes away. So I know it's no the A/C.
So here are the symptons:
When the car is cold, it squeals at every RPM. Horribly loud. It gets worse as RPMs climb.
Once it's warmed up fully the sound sort of goes away below 1500 RPM. Sort of - not always, but usually if I do a good bit of driving - say more than 20 mins worth. At which point there is barely any noticeable chirp at idle. But it always climbs with RPM.
What is this? How can I tell where the hell the sound is coming from? It's so loud you can hear it inside the car OVER the stereo. So trying to find it with the hood open is a nightmare.
But the problem is, I just can't stand it anymore! Car is all stock right now with a Power Bastards Alternator. Engine has 144k miles on it.
When I put the alternator on, it chirped a little, so I got a 1" shorter belt, and it didn't chirp. Everything was fine. Then one day it decided to start chirping like crazy. It hasn't stopped since then. I put the old belt back on, since it actually seemed to help (won't chirp when warm at idle with the factory length belt).
I put a new tensioner as well, thinking maybe there was still belt slip. Nada.
I've tried to chase down the sound, but it's so incredibly loud and overwhelming, I can't tell where it's coming from. I took the accessory serpentine off and it goes away. So I know it's no the A/C.
So here are the symptons:
When the car is cold, it squeals at every RPM. Horribly loud. It gets worse as RPMs climb.
Once it's warmed up fully the sound sort of goes away below 1500 RPM. Sort of - not always, but usually if I do a good bit of driving - say more than 20 mins worth. At which point there is barely any noticeable chirp at idle. But it always climbs with RPM.
What is this? How can I tell where the hell the sound is coming from? It's so loud you can hear it inside the car OVER the stereo. So trying to find it with the hood open is a nightmare.
Im glad i am not the only one with this problem!!! Its been driving me insane! By any chance would you be able to post the part number for the new belt you got? Did not know about having to switch the stock belt out for a shorter one until reading this post!!
Have you tried testing you pulleys by taking both belts off and giving them one good spin? If they spin more than a turn or two that pulley is usually bad. Theres a great video on youtube by lsxmovie. Just type in ls1 pulley. Goodluck on ur car man iv been chasing that damn squeal for months now i hope the new short belt will do it ive replaced three pulleys already!!! Ugh
04-28-2013, 12:32 AM
#39
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Tightening the belt has worked for me in the past. But after a few weeks the squeek comes back. I found out a few years ago that if you buy a gm factory belt this will remove the squeek noise at least for about 2 years than you replace with another gm factory belt. This is what i have done for many years now.
There was also a bulliten for this for the ls1 camaro it said to replace the alternator bracket with the new gm bracket. I bought the new gm alternator bracket but just havn't installed yet, sadly its been in the garage for years. But i got a squeek again and i may get to it this time before replacing wit a belt. I've tried other belts and nothing works but the gm belt.
There was also a bulliten for this for the ls1 camaro it said to replace the alternator bracket with the new gm bracket. I bought the new gm alternator bracket but just havn't installed yet, sadly its been in the garage for years. But i got a squeek again and i may get to it this time before replacing wit a belt. I've tried other belts and nothing works but the gm belt.
04-28-2013, 03:50 AM
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This only applies to '98 to mid-2000 cars. Mid-2000 to '02 came from the factory with the revised bracket and idler pulley.