Thread: Whining alternator?

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I was checking my tranny fluid today and noticed my alternator is making a whining sound, almost as if something is loose inside it. I still maintain 11.5-13v's but the noise definitley didn't sound normal. Is there any sort of eletronic cleaner I could spray in there or something to eliminate the screech? Or anything other suggestions?

BTW, It's only noticable when the hood is open - not so much when it's closed....


Thanks,
-gunz

Originally posted by bigazzgunz
I was checking my tranny fluid today and noticed my alternator is making a whining sound, almost as if something is loose inside it. I still maintain 11.5-13v's but the noise definitley didn't sound normal. Is there any sort of eletronic cleaner I could spray in there or something to eliminate the screech? Or anything other suggestions?

BTW, It's only noticable when the hood is open - not so much when it's closed....


Thanks,
-gunz

I DONT KNOW HOW MUCH ITS whining but all of them do to a degree. a low bat will make it whine more than normal. that 11.5 13 v ant nuthen to brag about though. a fully charged bat. should be around 13v. dont know for sure but it sounds like the alt. might be going bad. without any load on the alt it should be charging around 14v

Originally posted by techinspector1
ring, ring, ring,....hello, Autozone.....

i bet its chrome to.

Keep the hood shut and carry jumper cables!!!

I would caution against spraying anything into an alternator. As csf03716 says spin the alt by hand and if it feels rough it's time for bearings. Any decent shop manual should give you pretty instructions for doing it.

The good news is if you can do it yourself bearings and brushes (if it needs them) should be around $15. Bad news is if you send it to a shop to do your looking at about an hours labor ($50-60) plus parts mark up.

Before you do anything I would recommend electrically checking the alt to help decide if it's worth rebuilding. First check the voltage by running the engine at about 2000 rpm with the headlights on. If you don't have about 13.5 volts the alt is not putting out enough. If the voltage is low check the regulator if it's an internal regulator, there is a small hyole in the back of the case (again the shop manual will show you where it is EARLY GM ALT ONLY ) Insert a straightened paper clip or similar object in the hole. This in effect by-passes the regulator and full fields the alt. If the voltage comes up, the alt also needs a regulator. If the voltage is still low, you have either bad field or armature windings or a bad diode set.

Thanks for the input fellas. If I can isolate this issue to a bad alternator (yes, chrome), wouldn't it be easier to just pick up one of these? http://cgi.ebay.com/ebaymotors/ws/eB...category=33573

Originally posted by bigazzgunz
Thanks for the input fellas. If I can isolate this issue to a bad alternator (yes, chrome), wouldn't it be easier to just pick up one of these? http://cgi.ebay.com/ebaymotors/ws/eB...category=33573

that's a good price, i guess you're taking some chance. you could have someone check the voltage reg. and replace that if that's what's wrong, but time you pay someone to check it and buy the reg. you'll have 50.00 or more in it and the rest of the alt is still old. if you're conformable with buying it on e-bay, go for it.