Alternator Making Hideous Noise, But Still functions fine

I just had my tensioner and idler pulley replaced this morning hoping that those were making the nasty sound. Unfortunately the sound was coming from the alternator which clearly has some messed up bearings.

But it is having no issues charging the battery. Should I just wait until the alternator stops working as it is supposed to, or should I just go ahead and change it now?? I don't want to buy another alternator if there is no need because it is still charging the battery with zero issues.

So, anybody with experience want to weigh in??

a reply to: worldstarcountry

I'd change it now. Otherwise it will go out at the worst time imaginable. At least that's how things tend to work in my life.
Remember, luck favors the prepared.

a reply to: worldstarcountry

When those bearings go, they'll either seize, or blow apart.
Either way, you're getting a tow home. It will inevitably happen at the most inconvenient time.
If they seize, the belt will probably be destroyed before you cut the engine.

There's a chance you can just replace the bearings in the alt, but you'll most likely need to take it apart to figure out what bearings it takes... might not be worth the effort.

If you're broke, check out a junkyard for a replacement alt.

If it is the bearings and they are really worn, it hasn't got too much time left on it. They never seem to go out when it is convenient. Are you sure it is the alternator? Put a little piece of small hose next to your ear and listen to it as you touch the hose to the alternator. Rebuilt alternators are not usually that expensive, but they can be expensive on some cars. Try googling the price on a place like advanced auto. Some are really easy to change, others are lousy to change.

When I was into that, I would just change the bearing, they aren't that expensive and not hard to change if you have all the tools. I am lazy now, I just get a rebuilt one and stick it in. It could be the water pump though, or if your oil is low, it could be coming from the main bearing, that is why I always use a piece of hose before buying a new one.

a reply to: worldstarcountry

I would change it asap. I had one seize in a Ford Crown Vic and it caught fire. Thankfully I had a bottle of water to dump on the thing to put it out.

If anything with bearings (hard disk drive, ceiling fan, portable fan, alternator) is making bad noises and/or vibrating, it's on the road to failure. Better to have the minor inconvenience of losing a hour or two on a Saturday afternoon getting it repaired than to have the panic of getting it repaired before a tight deadline.

All of the above. Don't wait.

Remove the serpentine belt and spin the alternator. You can feel for rough bearings or even hear them if you spin it fast. If it doesn't spin smoothly, get it repaired or replaced.

Plus it's probably right on top in plain view and no more than four or five bolts.

a reply to: worldstarcountry

If the bearings are bad it will eventualy break...

Do you gamble or prefer a sure thing ?

a reply to: worldstarcountry

You would rather be stranded somewhere when the alternator has failed, locked up, and taken your serpentine belt and other minor parts with it into the junk yard? You are definitely failing to use good sense. Let me see your driver's license.

LOL! I keep a portable jumper always handy in each vehicle, as well as a fire extinguisher, 2ton pump jack and the usual default tools for working under the hood. And I do recall having the experience of failed alternators pissing me off. I just thought I would ask.

The gentleman that did my pulleys is a certified mechanic employed at a local Dodge dealer. He does side jobs for much better prices though, probably to fill his rainy day fund.

But, not only am I going to go ahead and replace the alternator per the collective wisdom of everyone's experience here, but I am going to try to see the difficulty in replacing those bearings as a self educational activity and see if its worth it in the future before I return the core. It'll probably just piss me off, but as long as I put those cast aluminum housings back on I don't think there will be an issue with the core right?

originally posted by: lordcomac
a reply to: worldstarcountry

When those bearings go, they'll either seize, or blow apart.
Either way, you're getting a tow home. It will inevitably happen at the most inconvenient time.
If they seize, the belt will probably be destroyed before you cut the engine.

There's a chance you can just replace the bearings in the alt, but you'll most likely need to take it apart to figure out what bearings it takes... might not be worth the effort.

If you're broke, check out a junkyard for a replacement alt.

And if the belt goes out, there is no telling what it might damage when it pops. I lost an alternator belt and it got caught in my AC compressor and burned that out. Guess what was far, far more expensive to fix?

a reply to: ketsuko
Ohh yea, does not sound pleasant at all. I'll just buy and install a new belt too. May as well, should only be like another $15-$20. Best to just get it out the way while im changing the alt.

Sometimes the grease gets washed out of the bearings. Some would rush to use lithium grease, but it's incompatible with other lubes. So, imo motorcycle chain lube is a good bet.

originally posted by: CharlesT
All of the above. Don't wait.

Remove the serpentine belt and spin the alternator. You can feel for rough bearings or even hear them if you spin it fast. If it doesn't spin smoothly, get it repaired or replaced.

This is the thing to do and while your at it, checks your water pump bearing for any play.

Glad you're replacing it, hope it's not too expensive or a pain.

I was REAL surprised when I thought mine was going out (right after I bought my truck) by how expensive they can get. Last time I did one it was like $150 and easy to do. This time it was over $400 for the alternator and Ford put the thing in a hard to reach spot.

Show us some pictures and maybe do a write up if you do replace the bearings.

If your alternator stops working your car will still run and drive. The issue is that all your electrical will then be running off your battery. And once the battery juice goes so does your ignition system and then the car wont run or start.

All the alternator does is charge the car battery once the car is started and it provides power to the accessories to your vehicle like the lights the radio etc....

I would be very careful letting it go on like this though. If the bearings seize it will cause your belt that drives the alternator to create friction between belt and pulley. Friction that will eventually break the belt. If your belt goes so does your water pump (that cools the engine) and your power steering will go with it. Now you have an overheating car with no power steering.


And don't bother trying to just replace the bearings or the pulley. It would cost you more time and money than just buying a rebuilt alternator from autozone and replacing it yourself. They are usually anywhere from 60 to 200 bucks just for the part. Labor is what costs the most.

a reply to: PraetorianAZ
My Labor is free. I only soicited Dodge man for the other pulleys because I did not feel like removing the tire and mud flap to get to the idler pulley. I had already did that three months ago when I replaced my own radiator. He charged me sixty, fair enough in my book. Thats about half or just a bit over having it done in shop.

The alternator in this Grand Caravan is just like sitting there with nothing over it. I don't got to do much other than take out a handful of bolts and loosen the tension. It will certainly be simpler than the radiator.

a reply to: worldstarcountry

warning sign to change it,sounds like bearings are worn,could hand grenade at anytime,leave you stranded

a reply to: worldstarcountry

warning sign to change it,sounds like bearings are worn,could hand grenade at anytime,leave you stranded