Alternator whine..........

redgtxdi

Diamond Member
Jun 23, 2004
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So, after driving my '95 Corolla to work yesterday & noticing the battery light flickering on /off & eventually staying on by the time I got to work, I knew I was in trouble.

Drove home as quickly as possible turning off lights when able........made it fine. (whew!)

Called AutoZone. Pulled old alternator (b!tch!!!) put new one in & all's well.

Noticed that the alternator whined a bit, so I loosened belt adjustment a little & while it helps, I can still hear it when the engine rpms are up while driving. It's not the popular "radio" whine, it's just a physical whine kinda' like a turbo sounds.

Will that break-in & go away or could it just be normal??

(P.S. Only thing I could think of was that cooling fins were "external" on the old alternator & the new one has 'em inside the casing.)
 

FeuerFrei

Diamond Member
Mar 30, 2005
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It's the bearings in the pulley whining. Means they are going bad. You can drive with it for a while, in my experience. I have a '93. Nippondenso is OE brand.
 

foghorn67

Lifer
Jan 3, 2006
11,883
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If you have a compressed air tools, you might be able to change the pulley from the old one.
 

redgtxdi

Diamond Member
Jun 23, 2004
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OK, maybe I didn't explain well.

Alternator's new. (Doubt bearings are going bad)

And my old alternator's bearings were toast & didn't make a sound.


And this particular sound is more like a turbo whizzzzzz. (thus me thinkin' that the cooling fins being internal might be creating the noise???)
 

Vette73

Lifer
Jul 5, 2000
21,503
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0
Take belt off Alt. Start car. If noise is gone look else where. If noise is still there then take Alt back and exchange.
 

foghorn67

Lifer
Jan 3, 2006
11,883
63
91
Originally posted by: redgtxdi
OK, maybe I didn't explain well.

Alternator's new. (Doubt bearings are going bad)

And my old alternator's bearings were toast & didn't make a sound.


And this particular sound is more like a turbo whizzzzzz. (thus me thinkin' that the cooling fins being internal might be creating the noise???)

I had an alternator that did that once, when I called the manufacturer (Powermaster), they said it was on high output mode. It stopped doing that after a few drives. I guess the battery had to topped off after being drained to almost nothing for a while.

After googling this, there could be several reasons. Some are pulleys, some are the wrong belt tension.
 

woodie1

Diamond Member
Mar 7, 2000
5,947
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I think once your battery is fully charged the noise will stop. If it doesn't in a few days then you may want to take it back.
 

redgtxdi

Diamond Member
Jun 23, 2004
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Ya, we'll see how it goes. It ain't enough to bother me, just that I was able to notice it.

I loosened the belt a little bit (didn't want slack it too much) and it's slightly less, but that's a friggin' fiasco in itself so that's as loose as she's gonna get for now.
 

marincounty

Diamond Member
Nov 16, 2005
3,227
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You should have bought a factory replacement alternator. Costs more but worth it.
I went through about 4 alternators and 3 regulators one time trying to fix my sister's datsun, these were Kragen parts. I learned my lesson the hard way.
I replaced the alternator on my '87 Corolla with a factory part about a year ago, no troubles.
 

Gillbot

Lifer
Jan 11, 2001
28,830
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Originally posted by: redgtxdi
OK, maybe I didn't explain well.

Alternator's new. (Doubt bearings are going bad)

And my old alternator's bearings were toast & didn't make a sound.


And this particular sound is more like a turbo whizzzzzz. (thus me thinkin' that the cooling fins being internal might be creating the noise???)

I've purchased many items "new" that didn't work at all when installed. Never assume it's not the cause just because it's "new".