New alternator whining

[Electrician]

Brand new alternator I ordered online Amazon Prime is whining right out of the box. It's not real loud but I hear it. I've heard some bad ones before that sounded like you were trying to tune in a radio station next to a megaphone. Now, the voltage is staying steady 14.5volts tho. So, my question is: should I return it or let it ride?

 

[Sam Harris]

Return it! Is it (supposedly) an AC Delco..?

Something so easy to swap, I’d return without question.

By the way, I had a genuine Delco from Summit shxt the bed after only about 5 months.

 

[B-train]

That would drive me nuts. I'd return it as well. The only time I want to hear an alternator whine is when I have the hood open and do a load test.

 

[Sam Harris]

Return it! Is it (supposedly) an AC Delco..?

Something so easy to swap, I’d return without question.

By the way, I had a genuine Delco from Summit shxt the bed after only about 5 months.

No worries though, they warrantied it. Took a while to get another one, but it’s now in my garage as a backup, once my cheap-a$$ Advance Auto one bites the dust. I was planning to swap them around, and might sometime I’m not busy, but not worried about the one that I’ve installed now.

 

[Doubeleive]

I have kids that whine already wouldn't want my vehicle doing it as well.

 

[RAMurphy]

I would return it. As already stated it is a simple remove and replace. It should not whine.

 

[Electrician]

It's not AC Delco. But I'm most likely gonna return it and get an AC Delco. This is an Amazon no name alternator. Now... it says it's an "aftermarket upgrade" and "rated for 255 amps". Anyone wanna chime in on how legit they think that 255amp claim is? Cuz I think I smell... bs
Anyway, being that it's such a high output (cough cough) model, it still shouldn't whine right?

 

[RAMurphy]

Due to my setup and audio system I replaced mine with a high output Mechman alternator that I bought directly from their site. A little more money but the quality and performance are outstanding. Been installed for nearly 100k miles and still running well.

 

[MassHoe04]

I agree. Return it.
There could be some poor machining on the armature or possible a bearing is bad right out of the gate. Either way, it will probably not survive as long as you would expect.

If I needed an alternator in a hurry, I would probably just order online to get 15-20% discounts and pick it up at the local NAPA store.
If not in a hurry, I would likely go to RockAuto and get a AC-Delco.
With these options, at least you know what you are getting.

With all I hear about different issues with parts from Amazon, I am not keen on going to them for parts right now.
For insignificant items or really cheap accessories, maybe. But serious parts, no...

I have had good luck through Ebay from legit suppliers known on the parts community (ones that are well known and have a solid online store presence, with high ratings.

 

[Joseph Garcia]

Return the alternator, and get a name brand alternator.

 

[Electrician]

Return the alternator, and get a name brand alternator.

I am. I already started the return process for Amazon, but I gotta wait til Saturday to actually unbolt it and go drop it off at a UPS store. My brother is gonna let me use his alternator off his 5.3 that's sitting right now. That way I don't have to spend money on another one until I get my refund. The 145amp AC Delco is already in my cart. Same price too

 

[Electrician]

AC Delco 145amp is ordered and will be here in a few days. Now I can get going on finding the stuff to rebuild my other one. Voltage regulator and rectifier assembly for sure and probably should do the smart thing and replace the bearings too. My brother told me something I never thought about when I was swapping on his alternator to borrow is that you're not supposed to use compressed air to blow out an old alternator. After years of heat, the thin coating on the windings gets brittle (but remains in place and still works most of the time) but blowing it with compressed air can strip off some of that coating to where it may not work properly. Interesting...

 

[Roll On]

I went through three alternators from different auto parts stores, all were rebuilt , finally gave up and paid double the price for a new one from the dealership, put it in and done.

 

[Doubeleive]

later on down the road if you decide to upgrade to a higher output the mechman as already mentioned is a great option, they take about 30-45 days or so to get to your door because they are built to order, mine has been on now for about 50k puts out 15v like a champ most of the time, the RVC controls that based on the battery temperature.
they are pricey though, they make different versions based on the rpm I wouldn't get one that restricts the max rpm's unless you really needed it that way for a special purpose.
the difference is the pulley size used generally, larger pulley for more output at low rpm's which means it can only be revved to xxxx rpm's without possibly ruining it.

 

[Doubeleive]

and to answer your other question, no more output does not mean it would make it whine, either it has a internal defect or there is a ground issue, sometimes a ground isolator will resolve that issue but it shouldn't be needed on a modern vehicle

 

[Electrician]

I know that one I just sent back was defective. I swapped in my brother's USED alternator and now it's running fine, no whine. I'll post up on how it goes with the AC Delco from Amazon. I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

 

[Doubeleive]

I know that one I just sent back was defective. I swapped in my brother's USED alternator and now it's running fine, no whine. I'll post up on how it goes with the AC Delco from Amazon. I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

YA, if I buy any oem parts off amazon I make sure it's the ac delco store, most of the fake stuff is smaller like knock sensors or spark plugs, bigger stuff is hard to replicate and still be profitable, other thing to watch for is bait and switch where they advertise it very much like a oem part but it's not.
then on the other end of the spectrum you have companys like "herko" that sell oem as there own brand

 

[afpj]

I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

yep, Last year I ordered a Delphi MAF as well as KYB shocks, they were both fake. The shocks may have had a bad batch of bushings, but just the packaging was different compared to the KYB box I got from rock auto. It ended up Rockauto being actually a few dollars cheaper too including shipping.

 

[Electrician]

RockAuto is a blessing for sure. My brother who's been a mechanic his whole life swears by them. He just doesn't like buying: 1)core-in parts or 2)wear parts that will likely fail before warranty expires, because the shipping process is too much hassle