I've had the same alternator on the car for 10 years. It always had a sort of whine, like it was spooling. Last few days it's been making some noises so I had planned to replace it tomorrow..Well on the way home last night it quit on me. I got up bright and early, hit the parts store and put in a new one (thinking the whine was just a symptom of use) I put on the new alternator, fired it up and it still whines. If anything its more robust. It sounds like a super charger. Is this common? The belts are new, PS pump and pulley are new and obviously the alternator, am I missing something? The belts for AC and AIR system have been removed long ago.

 

How does it sound and feel when you spin the pulley with the belt off?
How does this compare with the old one?

In general, alternators don't make noise, unless they're really putting out a lot of power.

- Eric

 

Sounds and felt fine. This new one is a little louder of a whine than the old one. I don't have anything that would pull a lot of voltage on the car. Just a cd player. If videos came be uploaded on here I'll take a sound clip and post it. It is that easy to notice. Batt is 12.5ish at rest, 14.5 @ idle. No spikes, dimming or brightness issues in electronics. I'm stumped.

 

12si alternators will whine a little bit(will be audible). it should not sound like a supercharger though. how is your water pump? here's a test... when the car is running, unplug the 2-wire connector on the side of the alternator, if it's the alt. it should stop whining. visually look at the connecter terminals to see if they are relatively clean and shiny. if not, you can clean them with some QD electronic cleaner and tarn-x if they are corroded. if you need to use tarn-x, rinse the plug and connectors in a generous amount of cold water. plug the 2-wire connector back in.


bill

 

Want some alternator cheese to go with that alternator whine?



Happy Independence day!

 

I'm gonna X2 Bill Demmer. I doubt if it is the alternator. Probably something else on the same belt (water pump?). It is probably louder now because the belt is tighter. Do what Bill said and if it makes no difference, try making the belt a bit loose and see if it quiets down some.

 

BBad alternator bearings sound much like a supercharger and live for quite awhile. What are the odds you got a new alternator with bad bearings though? Take the belt off and you should know then.

 

It's happened to me, so I guess that particular time I was in the auto parts store, the odds were 100:0.

- Eric

 

After some trouble shooting and listening close I'm starting to think it's the water pump. I have a high pitched squeak, getting the ear close it sounds like it's the water pump. alt is new, ps pump/pulley are new, belts are new and hayden 2747 HD clutch is new. Only old horse is the water pump. No issues with cooling or coolant circulation. Bad bearing? Pulley?

 

Sounds like a bad water pump - give the pulley a spin, and see if it's anything less than perfectly smooth.

- Eric

 

That would surprise me. As the water pump does not have a roller bearing like the alternator which will make a noise like that. But hell I'm wrong all the time anyway! keep us updated I'm curious.

 

Another piece to this I just noticed. This whine only starts to happen once the motor is at operating temp (160 w/ current thermostat)