What causes alternator whine on a 1991 Honda Civic DX
08-13-2007, 03:13 PM
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What causes alternator whine on a 1991 Honda Civic DX
After 185K miles of flawless service I replaced the OEM alternator with a rebuilt Bosch unit as a form of preventive maintenance. However, after only 25K miles this rebuilt alternator has developed a pronounced whine whose pitch is proportionate to the engine speed and whose loudness is proportionate to the amount of current output. When the car is started in the morning the whine is hardly noticeable. However, as soon as the headlights are turned on the whine begins and it continues as long as the engine operates.
1) Does anyone know the cause of this problem? Is this cause by worn bearings?
2) Will replacing the alternator solve the problem?
3) I have read that many rebuilt alternators are unreliable. Are Denso rebuilt units more reliable than Bosch?
Dennis Waller
1) Does anyone know the cause of this problem? Is this cause by worn bearings?
2) Will replacing the alternator solve the problem?
3) I have read that many rebuilt alternators are unreliable. Are Denso rebuilt units more reliable than Bosch?
Dennis Waller
08-13-2007, 04:20 PM
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Re: (umop-apisdn)
check the belt on the alternator i bet you put it on too tight causing the bearing in the alternator to go bad..try loosening up the belt some..see if it helps
08-13-2007, 04:24 PM
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Re: What causes alternator whine on a 1991 Honda Civic DX (DennisWaller)
A fried diode in the alternator will make a very nasty squealing sound, and I'm sure that is what it is, as load increases, the blocked current fights the electromagnetic induction of the alternator, making a very pronounced whine, Chevy Malibu's by far have the loudest.
Sounds something like this? this one is fairly bad, the ELD picked it up and cut the current to the alt field circuit after like two seconds, but most cars wont, because the current will simply ground itself into the stator again.
http://www.youtube.com/watch?v=8894l59nb3s
Sounds something like this? this one is fairly bad, the ELD picked it up and cut the current to the alt field circuit after like two seconds, but most cars wont, because the current will simply ground itself into the stator again.
http://www.youtube.com/watch?v=8894l59nb3s
08-13-2007, 05:30 PM
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Re: What causes alternator whine on a 1991 Honda Civic DX (DennisWaller)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DennisWaller »</TD></TR><TR><TD CLASS="quote">3) I have read that many rebuilt alternators are unreliable. Are Denso rebuilt units more reliable than Bosch?</TD></TR></TABLE>
This is true.
Through trial and error, we have determined that Bosch remans have a much lower failure rate than the vast majority of remanufactured alternators out there, though the additional expense is not negligible.
Denso typically maufactures better electronics systems than Bosch, and most Denso parts have an even lower failure rate than Bosch. If the Denso reman is indeed actually remanufactured by Denso, I'd go with that.
http://www.densoaftermarket.com/products/?id=14
This is true.
Through trial and error, we have determined that Bosch remans have a much lower failure rate than the vast majority of remanufactured alternators out there, though the additional expense is not negligible.
Denso typically maufactures better electronics systems than Bosch, and most Denso parts have an even lower failure rate than Bosch. If the Denso reman is indeed actually remanufactured by Denso, I'd go with that.
http://www.densoaftermarket.com/products/?id=14
08-13-2007, 06:14 PM
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Re: (305accord)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 305accord »</TD></TR><TR><TD CLASS="quote">check the belt on the alternator i bet you put it on too tight causing the bearing in the alternator to go bad..try loosening up the belt some..see if it helps</TD></TR></TABLE>
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08-14-2007, 09:38 AM
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Re: What causes alternator whine on a 1991 Honda Civic DX (DennisWaller)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DennisWaller »</TD></TR><TR><TD CLASS="quote"> I have read that many rebuilt alternators are unreliable.</TD></TR></TABLE>most are unreliable - better off going to the junk yard and getting a used OEM - it will last just as long, if not longer, than a rebuilt
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