Is my alternator about to die?

[slashnick]

I have posted about the high pitch whine in my engine compartment, on the drivers side. I tried to pinpoint it with a stethoscope but had some trouble. I was told if the volts are below about 14.5v the alternator is about to go. Lately it has been between 13.9 and 14.3v. I dont think the whine has got louder, hard to tell. This has been going on for about 2 and a half weeks. Is my alternator about to die?

-matt

 

[chevyaddict]

Well, our alternator "bearings" go out quite often on our 84 - don't really know why. I think your volts are fine - that small difference is miniscule and each car is a little different. However, the whine might just be your bearings giving out. Eventually the bearings will freeze and then your belt will start smoking if you don't shut the motor off right away. I would suggest taking the belt off and free spining the alternator and smog pump - maybe even the water pump too just to try and limit the possibilities.

Dawn

 

[Ken]

I don't mean to scare you, but I've had people tell me they won't leave town without a spare alternator. I, however, have driven across the country, with a spare on board, but never used it. Go figure.

_ken

 

[ocrick]

Your volts look fine. I would get concerned if it gets below 12.8V at idle. I had an alternator go a couple of months ago. Got in it one night fired it up and started home. I notices my dash lights seemed a little dim so I switched on the voltmeter on the dash and it read 10.6V!!!

The further I went the lower the voltage dropped. I turned off my headlights (everybody was flashing theirs at me) and when it got to about 10.1V my ABS computer shut down and my idle was really rough.

I finally got home at 9.8V and put the battery on the charger....it wouldnt take a charge at all. Since I had to go to work the next morning I borrowed the wife's car and ran to the parts store to get another alternator. Installed it and with the new alternator the battery charger charged the battery right up. I think there was a short in my alternator.

Anyway....NO WARNING! No whine, no dash charge system warning light...zippo.

I got the 105 amp alternator this time....but next time I will opt for the 140 amp one because if I fire up all of the electrical loads: radio, HIgh beam headlamps, high fan on AC it will only put out 11.9 to 12.1V at idle.

 

[Bob 89]

DITTO. Your volts are fine.

Bob

 

[oldace84]

I replaced the alt on my '84 with a Tuff Stuff Chrome unit rated at 140 amp's......seems to be doing its job, even with the March Pulleys....
Great!!!!!!!
tony

 

[Edmond]

These are two sure signs that your alternator is going downhill:

1. your MPG has gone down for no obvious reason like cold weather, etc...

2. the car doesn't accelerate like it should.

 

[sumoboy]

Well, our alternator "bearings" go out quite often on our 84 - don't really know why. I think your volts are fine - that small difference is miniscule and each car is a little different. However, the whine might just be your bearings giving out. Eventually the bearings will freeze and then your belt will start smoking if you don't shut the motor off right away. I would suggest taking the belt off and free spining the alternator and smog pump - maybe even the water pump too just to try and limit the possibilities.

Dawn

The bearings could be going up and it can still be charging because the brushes are still good.