Alternator making a whining noise

[Mark72]

I replace my alternator because it was making a constant whining noise going down the road and I was getting electrical burning smell from it. Particularly when the engine was under load. And the brand new one does the same thing. Not the burning..just the same whine. Is that normal with some alternators? Note...there is no spring tensioner. You only tighten the belt down. My friend thinks it's because the belt is too tight. Is that also another posibility that it could be putting too much tension on the barrings?

 

[Nick1994]

How sure are you that it's the alternator?

 

[AjsGarage]

Originally Posted By: Nick1994
How sure are you that it's the alternator?

I'm with this guy

 

[Mark72]

I went around it with a stethoscope and isolated the noise

 

[The_Eric]

Bad or weak battery making the alt put out big amps and overheating? have seen a few alternators die like this. Also it's not uncommon to hear an alt whine when it's working really hard.

 

[Mark72]

Like working really hard because the belt is too tight?

 

[MolaKule]

Originally Posted By: Mark72
Like working really hard because the belt is too tight?


Yep, back off the tension.

 

[DoubleWasp]

Some are just loud. Ford 4G alternators come to mind. Moment they turn on....whiiiiIIIIIIIIRRRRRRRR

 

[KitaCam]

Just unplug the ALT while running to isolate the sound...if no whine then it's the ALT...if still whining then perhaps a pulley bearing?

 

[ragtoplvr]

Alt has 3 sets of current producing windings. if one set fails, it makes a wining noise because forces are not balanced. Alternator will not put out full current either.

Never use a cheap (china) all new alternator to recharge a battery, many brands can not take the extra load.

A local rebuilder can often do a better job

rod

 

[The_Eric]

Originally Posted By: ragtoplvr
Alt has 3 sets of current producing windings. if one set fails, it makes a wining noise because forces are not balanced. Alternator will not put out full current either.

Never use a cheap (china) all new alternator to recharge a battery, many brands can not take the extra load.

A local rebuilder can often do a better job

rod



Never use ANY alternator to recharge a low battery.

 

[Bamaro]

It could have the bearings starting to go.

 

[SirTanon]

What car is this on? On my car, I thought the alternator was going, but it turned out to be failing bearings on the belt tensioner. Sounded just like a bad alternator or tranny. Even got faster with engine revs.