03 LS Alternator Replacement due to bad bearings?

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yabadaba

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My mechanic told me my alternator pulley bearings are going bad. There is squeaking on start up but after car gets warm it seems to go away. ( he diagnosed this after changing my belt twice)The charging system is ok. Should I replace the alternator just to get the new pulley? I don't have the means to change the alternator myself. Any advice is appreciated.


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yabadaba said:
My mechanic told me my alternator pulley bearings are going bad. There is squeaking on start up but after car gets warm it seems to go away. ( he diagnosed this after changing my belt twice)The charging system is ok. Should I replace the alternator just to get the new pulley? I don't have the means to change the alternator myself. Any advice is appreciated.


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Click to expand...

When I had chirping for a few seconds on start-up when it was cold the culprit was the tensioner.

IMHO he's not much of a mechanic if it takes him 3 times to find a noise. You can do this test yourself; get a long screwdriver or piece of metal. With the engine running CAREFULLY, taking care to avoid the moving parts, touch the alternator (avoid any electrical connections) and see if you can hear the squeal by putting your ear to the "probe". If you can you've found the source. If not, it's coming from somewhere else.

I'm pretty sure the bearing isn't a serviceable part so you'll need a new (actually rebuilt as new aren't available) alternator. Expect to pay around $600 installed.
 
LS4me said:
When I had chirping for a few seconds on start-up when it was cold the culprit was the tensioner.

IMHO he's not much of a mechanic if it takes him 3 times to find a noise. You can do this test yourself; get a long screwdriver or piece of metal. With the engine running CAREFULLY, taking care to avoid the moving parts, touch the alternator (avoid any electrical connections) and see if you can hear the squeal by putting your ear to the "probe". If you can you've found the source. If not, it's coming from somewhere else.

I'm pretty sure the bearing isn't a serviceable part so you'll need a new (actually rebuilt as new aren't available) alternator. Expect to pay around $600 installed.
Click to expand...

I needed a new belt so they changed it but once the squeal came back, they changed the belt again. At that time he determined it was the alternator pulley not the belt but I will use your test to see if I can confirm if he is right.



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The bearings are in the alternator, not the pulley. The pulley on the alternator can be changed without changing (or even removing) the alternator. However, your problem is not going to be the pulley.

From your description, the belt tensioner is more likely to be the problem. Just because the belt squeaks when the alternator adds a load to it, does not mean the alternator is at fault. If you turn the AC on before the car warms up, does that also cause a squeak?

I am going to assume that you have a parts changer, rather than a mechanic that can do real diagnostics.
 
Quote LS4:

"IMHO he's not much of a mechanic if it takes him 3 times to find a noise."

Quote Joe:

"The bearings are in the alternator, not the pulley. The pulley on the alternator can be changed without changing (or even removing) the alternator. However, your problem is not going to be the pulley. ... I am going to assume that you have a parts changer, rather than a mechanic that can do real diagnostics. "


+1 on both comments. As LS4 suggested,,, CAREFULLY use a screwdriver at the bearing points on the alternator... and keep it away from any rotating parts. Joe has a good suggestion with the tensioner. The only way to tell for sure is to probe around. Bad bearings will give a scraping/whining sound when bad.. when probed with a stethesope or screwdriver, (AGAIN... watching out for rotating parts). Alternators can be rebuilt,,, and parts are cheap... IF you know what you are doing. If you don't know what you are doing,,, but have a local starter/alternator rebuilding shop in your area... they could rebuild your alternator with new bearings and brushes for about $100 or a little more. IF you KNOW what you are doing... then you could rebuild the alternator yourself for about $35... as long as it's still charging properly. If not charging properly,,, add about $100 for a rectifier assembly,,, or pay maybe $250 for a rebuilt alternator... with you installing it yourself.

Again... Joe has a good idea to check tensioner and idler bearin pully bearings,,, but it may still be the alternator. If you want a quick fix to see if it's the belt. Buy some belt dressing lube,,, and see if the noise stays gone.
 
04_Sport_LS said:
Quote LS4:

"IMHO he's not much of a mechanic if it takes him 3 times to find a noise."

Quote Joe:

"The bearings are in the alternator, not the pulley. The pulley on the alternator can be changed without changing (or even removing) the alternator. However, your problem is not going to be the pulley. ... I am going to assume that you have a parts changer, rather than a mechanic that can do real diagnostics. "


+1 on both comments. As LS4 suggested,,, CAREFULLY use a screwdriver at the bearing points on the alternator... and keep it away from any rotating parts. Joe has a good suggestion with the tensioner. The only way to tell for sure is to probe around. Bad bearings will give a scraping/whining sound when bad.. when probed with a stethesope or screwdriver, (AGAIN... watching out for rotating parts). Alternators can be rebuilt,,, and parts are cheap... IF you know what you are doing. If you don't know what you are doing,,, but have a local starter/alternator rebuilding shop in your area... they could rebuild your alternator with new bearings and brushes for about $100 or a little more. IF you KNOW what you are doing... then you could rebuild the alternator yourself for about $35... as long as it's still charging properly. If not charging properly,,, add about $100 for a rectifier assembly,,, or pay maybe $250 for a rebuilt alternator... with you installing it yourself.

Again... Joe has a good idea to check tensioner and idler bearin pully bearings,,, but it may still be the alternator. If you want a quick fix to see if it's the belt. Buy some belt dressing lube,,, and see if the noise stays gone.
Click to expand...

I tried the screwdriver test with no change- maybe I did it wrong. Can I try and add tension with a breaker bar and see if the noise goes away? I saw remanufactured alternators for sale at autozone for about 150.


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The "screwdriver test" was not supposed to cause any change. You are supposed to use it to see if you can hear the sound through the screwdriver, which would indicate that you are touching close to the source of it.

Do not try to add tension with a breaker bar to the tensioner while the engine is running. There are several very bad things that could happen to you while doing that.
 
joegr said:
The "screwdriver test" was not supposed to cause any change. You are supposed to use it to see if you can hear the sound through the screwdriver, which would indicate that you are touching close to the source of it.

Do not try to add tension with a breaker bar to the tensioner while the engine is running. There are several very bad things that could happen to you while doing that.
Click to expand...

Ok, can you clarify where I am to touch w the screwdriver? And do I continue to try different locations until the squeak is amplified?
Also, I hear conflicting things about using belt dressing; primarily never to use it.


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Here's a video: https://www.youtube.com/watch?v=U927cYhQXB4
touch the blade end of the screwdriver to the non-moving parts each accessory (like the alternator) as you are locking for the problem. Note that if you are looking for a squeak or squeal instead of a rattle or moan, this probably won't work.
Also note that I use one of these: http://www.harborfreight.com/mechanics-stethoscope-69913.html as I consider it safer, more reliable, and cheap enough.

Belt dressing won't fix anything for more than a day or two. I've never tried it.
 
yabadaba said:
saw remanufactured alternators for sale at autozone for about 150.
Click to expand...

Do yourself a favor and get the FOMOCO reman unit. Unless you like replacing the alternator every 6 months or so. They cost more but will have a "normal" service life vs. the crappy service life of the AutoZone unit. I got to help my bother-in-law change out an AutoZone lifetime alternator at the side of a rainy back-country road. It filed after a few thousand miles. I've had the same success with their alternators (I've replaced 3 on the same car).
 
When I needed an alternator, the only one who had one on a Saturday afternoon was Autozone. It lasted several months and failed on the starting line at the Maxton, NC, ECTA track. A quick trip into town got another and we changed it in the dirt in the pits with a flashlight that night.

I needed to change it a couple of more times on an every few months basis. But the last iteration lasted for five or six years before it conked-out again the other day. Hopefully this next one will last at least another few years before needing to be replaced. Right now it's about 12 degrees out so the car is just setting.

KS
 
^^^ And you say my reaction is kneejerk when I go for OEM parts first... and that I distrust anything that doesn't come over a dealership parts counter??? I think you just kinda proved my point. Not being snippy,,, I'm just sayin............
 
I noticed that when the engine is adequately warm when I started up with the remote start, and it's on for about 10 minutes before I get in there is actually no noise from the belt or anywhere.thoughts?


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Well, we really need to hear the noise. Is it a squeak, squeal, chirp, roar, grinding, rattling, or whatever sound? Can you record it and post that?

Typically, a squeaking or chirping when cold and not warm points to a worn out tensioner or a failing damper pulley.
 
Here is some video/audio of the engine while cold. I noticed that any additional load (defroster, high beams, etc) causes a change in noise/frequency. https://vimeo.com/198931563


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Looks like you need VCT seals.
What I could see of your damper pulley looked okay.
It could be the alternator, but it could also be the water pump, power steering pump, or AC clutch. However, I think it's more likely to be the tensioner and/or idler pulley. Also what brand of belt did you use?
 
Yeah... I was gonna suggest the idler pulley. Isn't that a known issue with certain year LS's Joe???

yabadaba,

The only reason I suggested the belt dressing, (or wax candle... or a bar of soap),,, was to rule out that it was the actual belt or one of the pulleys
 
04_Sport_LS said:
Yeah... I was gonna suggest the idler pulley. Isn't that a known issue with certain year LS's Joe???

yabadaba,

The only reason I suggested the belt dressing, (or wax candle... or a bar of soap),,, was to rule out that it was the actual belt or one of the pulleys
Click to expand...

I see; would using the dressing help with process of elimination? It seems like a cheap way to do so.

Joe, it was a generic belt and I am not sure what kind. (The 2nd Time I went to the mechanic for the noise he said he put a smaller belt on)

So what would you guys recommend as a first step?


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Personally, I would replace the idler, the tensioner, and the belt (get the Ford/Jaguar belt this time, they last for over 100K miles). I would most certainly throw out that shorter belt and put the correct length one in. That's potentially adding stress to everything the belt drives. Never go back to that "mechanic."

Even if these aren't the source of the noise (but they probably are), they are wear items that are needed sooner or later. You don't want one to fail in operation and cause expensive damage.
 
yabadaba said:
My mechanic told me my alternator pulley bearings are going bad. There is squeaking on start up but after car gets warm it seems to go away. ( he diagnosed this after changing my belt twice)The charging system is ok. Should I replace the alternator just to get the new pulley? I don't have the means to change the alternator myself. Any advice is appreciated.


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Click to expand...
I had the same intermittent squeak. Replaced the alternator. Never happened again.

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Yabadaba,

Yes... lubing the belt with any of above suggested materials,,, would be first process of elimination for the belt and pulleys. You would want to both sides of the belt,,, since the belt runs on some smooth pulleys too.

As Joe said,,, get rid of that shorter belt. It can cause more damage.

Quote Joe:

"You don't want one to fail in operation and cause expensive damage."

Like shredding and taking out the front seal on the crank??? Read that recent thread yabadaba.
 
Ok. So I tried something I read; I put some baby powder on the belt. The chirp went away. Does it mean anything?


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yabadaba said:
Ok. So I tried something I read; I put some baby powder on the belt. The chirp went away. Does it mean anything?


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Click to expand...

To me, it would point to the tensioner and the belt.

I don't see how baby powder on the belt would make an alternator bearing quiet down, but I guess never say never.
 
Lol. So it's likely NOT the alternator or other accessories...Ok so it seems narrowed down. I can order the belt now and the tensioner tomorrow. So basically the mechanism in the tensioner is shot.


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