Well as some know i pulled the alternator last week cause it was making this loud whining noise. I took it down to the shop that rebuilt it some time ago and there was a screw missing and one loose. These hold it together. He said the whining was because thing inside were not centered right with the missing and loose screws. He tighted everything up and tested it and it came out perfect on the tester. I took it home and put it back in the vette. About 75% of the whining noise went away but a little was still there. He said it was normal for an alternator to make a little noise but i never heard this before but maybe was hypersensitive to it now. Anyway i noticed that the voltmeter in the car went back to where it used to be months ago which is pegged down near the bottom (18), not all the way down but far away from the center of the guage where it gradually crept to ever the last several months. Anyway last night i had the car out and i heard somewhat loud whining again. The guage would start out at about halfway on the guage and then once i got moving would move to where i like it (near the bottom). Is this normal? I can't remember but i am pretty sure that in the spring the guage pretty much stayed near the bottom. Also what about this whining noise. It was just tested Friday and the alternator came out beautiful on the tester. I was at my parents this weekend and my dad has a chevrolet pickup with a 350 in it. I listed to his and heard no alternator noise. The noise on my car is definitely the alternator because when i disconnect the cable to it the noise goes completely away. What do you all think??

 

There are a number of reasons why alternators make noise, bearings, laminations vibrating, coils moving, internal fan blades. Noise doesn't necessarily mean a defective alternator, but they are designed and constructed to be quiet. Apparently you don't have a quiet one. The output voltage is determined by the voltage regulator and it should be 14.7 v cold and this will drop to 13.7 hot. Your dash voltmeter needs to be checked against a voltmeter directly across the battery terminals. GM says the alternator could be as high as 16 v output. I wouldn't worry about it .

 

Check the output with a meter and it should be around 14 VDC. I am just woundering if when the screws where loose if any damage was done to the bearings?

 

I am wondering myself as before i pulled the alternator that night i could see the occasional spark from inside. The shop said that if they are sitting right inside things will run where they should not. He reassured me they tested the alternator and it was golden. He has nothing to lose here as its not under warranty he could always tell me its done and i need a new one. Anyway i am just irritated by this noise (maybe it was always there) and also why the needle on my dash will sometimes be near the halfway mark and other times be near the max reading. Is that normal?? I though i remember mine used to always be near the max point IDK. I really dont feel like pulling it again for no reason. Any input is helpful :cheers:

 

doesn't sound good to me... mines quite as can be.... def check the volts output...

 

:iagree: I would get that voltage checked to make sure you aren't going over the normal amounts. Mine guage has always been around the 60-75% mark and never any higher. My digital readout is stating 14.7 cold and the 13.7 +/- .2 volts at all times hot. I also run silent.

I don't know what else to recommend. If the meter is pegging, then something is wrong someplace because it shouldn't do that (be it guage or alt or both). Good luck...

 

its never pegging. I would say it's at about 80% most of the time. Recently before i pulled the alternator there was a lot of intermittent whine at the guage would be right in the middle. Mow its at the middle whwn i start it then goes to the 80% mark when driving.