Carquest Alternators Noisy?

[Fitz98]

A couple years back my OE alternator went out on my 03 Suburban 5.3 while on a road trip. Fortunately, I was close to a parts store and was able to limp in with no headlights at 8:30 at night and get a new Carquest alternator at Advanced Auto to put on.
As soon as I put it on, the first thing I noticed is that it worked, the second thing I noticed was there was a new whining noise.
I lived with it for a couple years, but now that I had it off, I checked the bearing and it was a little rough. Not bad, but if you hold the alternator just right, you could feel a little vibration/rough spot when spinning the pulley. I thought I had a bad alternator from the beginning. Went to AA and got a replacement under warranty.
Spun the new pulley and it feels and smooth and sounds quiet. I put it on and it is still whining. I guess that is just the nature of these?

New water pump, new power steering pump, new drive tensioner, new ac tensioner, new alternator, new belts, new idler pulley.

 

[TCL]

A couple years back my OE alternator went out on my 03 Suburban 5.3 while on a road trip. Fortunately, I was close to a parts store and was able to limp in with no headlights at 8:30 at night and get a new Carquest alternator at Advanced Auto to put on.
As soon as I put it on, the first thing I noticed is that it worked, the second thing I noticed was there was a new whining noise.
I lived with it for a couple years, but now that I had it off, I checked the bearing and it was a little rough. Not bad, but if you hold the alternator just right, you could feel a little vibration/rough spot when spinning the pulley. I thought I had a bad alternator from the beginning. Went to AA and got a replacement under warranty.
Spun the new pulley and it feels and smooth and sounds quiet. I put it on and it is still whining. I guess that is just the nature of these?

New water pump, new power steering pump, new drive tensioner, new ac tensioner, new alternator, new belts, new idler pulley.

Does it only happen when the wife or girlfriend is in the vehicle?

 

[Fitz98]

Literally made me laugh out loud

 

[chainblu]

I don't know who makes alternators for Carquest, but I recently replaced the one in my Silverado (200,000 miles) with a new AC Delco. Like you, first thing was that it worked, then I noticed a whine. I just returned from a 1500 mile road trip with no issues, but I did have the old one behind my seat, just in case.

 

[wrcsixeight]

I had a rebuilt alternator whine. ABout 20K miles later it quit charging.

When I opened it up I saw the sliprings were not installed properly and the lower brush was touching both slip rings.

I rehoned the sliprings spinning the pulley with a wire brush on an angle grinder on a router speed controller

I modified the brush holder to sit lower, improved some heatsinking, tried to reduce some electrical resistance and now, it can exceed (slightly) its 120 amp rating.

Remanufactured alternator brush alignment

Looks like they missed, badly. Surprisingly it worked fine for 4.5 years like this~25k miles, and often, it was told by my adjustable voltage regulator, to make everything possible towards its 120 amp rating, feeding a large depleted low resistance AGM battery, over a thick copper circuit.

bobistheoilguy.com

 

[GMBoy]

Getting good auto parts, even from well known reputable brands, has been a complete crap shot now a days. I am seeing so many parts with terrible quality and dead on arrival since this pandemic. Prior to all this "new normal" parts were reliable and rarely bad - I am not making this up but I estimate that more than 40% of the parts I get to the shop are either bad or shoddy in some way. Add to that many parts are simply not available/back ordered and the car repair market is very jacked up right now.

 

[Fitz98]

I don't know who makes alternators for Carquest, but I recently replaced the one in my Silverado (200,000 miles) with a new AC Delco. Like you, first thing was that it worked, then I noticed a whine. I just returned from a 1500 mile road trip with no issues, but I did have the old one behind my seat, just in case.

Was the new Delco alternator the Professional/Gold series or OE Delco? All I can seem to find in the AC Delco OE line are rebuilds, so I am not sure what they are using for the rebuild that gives them confidence to still stand behind the OE label.
The whining is annoying and was thinking to go back to OE or getting a junk yard core and having it re-built. This Carquest has worked fine other than the whining, so I would hate to waste any more money on a new alternator of any brand and still have the same problem.

 

[clinebarger]

Alternators do make noise naturally while charging depending on the load....But it's more of a hum than a whine.

GM part# 22781131 will work on your '03 Burb & is a 100% new OE DR44G 145amp alternator. Even though the number won't cross to a '03 Burb.

A bunch of these were run for Chevrolet Performance Parts Division which doesn't normally (hardly ever) deal in remanufactured parts.

​

 

[D60]

All I can contribute (which I repeat hoping perhaps it will allow my aging mind to actually retain what I recently learned):

When checking bearings on something like an alternator a cursory grab 'n shake of the pulley is insufficient.

If the REAR bearing has failed you must imagine you're looking for play at the opposite end of a long lever and the fulcrum is right at your body, so you must "bear down" and "tip up" on the pulley accordingly.

This is obvious to most but I drank motor oil as a kid so I'm slow to learn and quick to forget

 

[chainblu]

Was the new Delco alternator the Professional/Gold series or OE Delco?

I couldn't remember so I had to look at the box that's still sitting behind my seat. It was the Professional series. The whine isn't loud enough to be heard inside the cab with road noise, etc, but it's definitely louder than the original. I'm actually more concerned about how hot it runs. It seems very hot to touch after running a while, but I never really noticed how hot the original ran, so maybe it's normal. Time will tell....

 

[zzyzzx]

Alternators do get very hot normally.

 

[wrcsixeight]

How hot depends on the load.... how many amps they need to make to maintain the voltage chosen by the regulator How fast the fan(s) spin, and underhood airflow, are also infuencing variables.

At low rpm an high load, expect them to get hot. 220f+ is too hot.

 

[Dave9]

If you think it's the bearings then I'd just replace the bearings, unless you can get a refund to put towards another brand.