Alternator Noise (mechanical failure)

i am hearing a whirring noise, lower pitch than supercharger whine on acceleration, its not terribly loud but i can hear it from inside of the car with the windows up. but before i assume something, what does a spun bearing sound like? how do i find it etc. of course this noise appears after i put the pcm in and have a bit of fun... geez

A spun rod bearing causes a low pitched knocking sound under load,  usually once per revolution. You can hear it in P if it's really bad. Doesn't sound like your problem. Unless you let it run out of oil, don't know why this would happen.

ok good i definitely dont hear that noise lol. it sounds like  a hum in the engine compartment. i turned the steering wheel back and forth didnt hear the powersteering pump, but gave it alittle gas in park and i could hear it. strange

in the morning i will check all of my fluids and go from there

Could be a failing alternator bearing. After a drive, touch the alt housing to see if it's hotter than other parts on the engine. Can also remove the accessory belt and rotate the alternator pulley by hand. Check for rough rotation, squeaks, or wobble/play.

Alright, will do

also get a long screw driver touch it to the alternator (NOT ANY ROTATING PARTS)... Just the case and put it to your ear.. if you hear a knocking noise you can imagine your alternator is bad.. or take the belt off and spin the pulley.

AA wrote:

Could be a failing alternator bearing. After a drive, touch the alt housing to see if it's hotter than other parts on the engine. Can also remove the accessory belt and rotate the alternator pulley by hand. Check for rough rotation, squeaks, or wobble/play.




(what he said lol.... whoops)

Lol thanks, I took the belt off and spun the pulley, now I know there would be noise coming from the brushes but the squeak is louder and theres a sound of metal rubbing metal, you know, the white noise sound. Recorded it  and sent it to one of my mechanically inclined friends, " yup, shes done " lol, ok what are our alternators

Pay for a good one: $200-250 fully rebuilt usually. Don't buy the cheaper option - its a partial rebuild.

Alright

You could also take it as a mod opportunity and get a 220 amp alternator if you plan on doing any audio stuff later on.

Which parts aren't replaced on the partial rebuild?  Also how many volts should a good alternator put out?

A rep at NAPA told me they sell remans at two price points. The lower price is for a cleaned-up unit with refurbished rectifier diodes and brushes, but the mechanicals aren't touched. The higher price point ($50-75 more) includes a new bearing in addition to the electricals, a full rebuild.

Cores with bad bearings get fully rebuilt. Cores with only bad diodes will likely be partially rebuilt.

Either the same source or possibly an AutoZone rep told me that 1 in 4 of the alternators they sell come back defective. This actually happened to me once. Brand "new" alternator put out incorrect voltage, really confused me for about 15 mins.

I bought the cheaper AC Delco one (didn't know it was a partial rebuild), but it looks brand new on the outside.  I'll have to check the information that came with it and see what it says.

EDIT: I just checked the box and it doesn't mention if the bearing have been replaced or not.  The book also said it should produce 13.5 - 15.1 volts.

Wouldn't hurt to ask the vendor you purchased from. You might call in as a customer interested in buying an alternator, not someone who's already purchased one, if you know what I mean.

highwaywarrior....NAPA has a 150A Alternator for the Riv. If I remember correctly it's like $150 or so. Runs my 2500 watts just fine

@98 Riv: In my experience the ACDelco remans are superb.  IDK if they are still doing this BUT what I was told they did was they took an "obsolete" manufacturing line and set it up to remanufacture alternators.  They make the remans out of a mix of new and used parts that meet new specs.  Old alt cores that come in are broken down and scavenged.  The cases are checked and almost always reused.  IIRC the bearings are always new, the brushes always new, and  the electricals (diode pack) usually new but definitely meeting new specs.  They are then 100% tested to spec.  The only problem I've had with one is I got one from gmpartsdirect.com that had been dropped on the pulley, damaging the pulley.  I popped the pulley off the old one and sent them the old core back with a "here's the pulley you all sent me" note...  As such that reman is still on my Riv, been there for years.  It has lasted longer than the one that came new on the car and also longer than the NAPA reman that went before it.  I guess it is fair to say you should get your money out of the ACDelco reman.

albertj wrote:

@98 Riv: In my experience the ACDelco remans are superb.  IDK if they are still doing this BUT what I was told they did was they took an "obsolete" manufacturing line and set it up to remanufacture alternators.  They make the remans out of a mix of new and used parts that meet new specs.  Old alt cores that come in are broken down and scavenged.  The cases are checked and almost always reused.  IIRC the bearings are always new, the brushes always new, and  the electricals (diode pack) usually new but definitely meeting new specs.  They are then 100% tested to spec.  The only problem I've had with one is I got one from gmpartsdirect.com that had been dropped on the pulley, damaging the pulley.  I popped the pulley off the old one and sent them the old core back with a "here's the pulley you all sent me" note...  As such that reman is still on my Riv, been there for years.  It has lasted longer than the one that came new on the car and also longer than the NAPA reman that went before it.  I guess it is fair to say you should get your money out of the ACDelco reman.

Thanks

98riv wrote:

albertj wrote:

@98 Riv: In my experience the ACDelco remans are superb.  IDK if they are still doing this BUT what I was told they did was they took an "obsolete" manufacturing line and set it up to remanufacture alternators.  They make the remans out of a mix of new and used parts that meet new specs.  Old alt cores that come in are broken down and scavenged.  The cases are checked and almost always reused.  IIRC the bearings are always new, the brushes always new, and  the electricals (diode pack) usually new but definitely meeting new specs.  They are then 100% tested to spec.  The only problem I've had with one is I got one from gmpartsdirect.com that had been dropped on the pulley, damaging the pulley.  I popped the pulley off the old one and sent them the old core back with a "here's the pulley you all sent me" note...  As such that reman is still on my Riv, been there for years.  It has lasted longer than the one that came new on the car and also longer than the NAPA reman that went before it.  I guess it is fair to say you should get your money out of the ACDelco reman.

Thanks

...also for the rest of you reading this, a junkyard alternator is usually a pretty good bet.  People do not usually junk their cars over alternators.

there is a noise coming from my engine, when i press the gas there is a whirring noise from engine and when i let off it makes the same noise, thought it was the supercharger so i took the belt off and ran it, same noise!!! someone call or text me @ 7 5 7 6321746 so i can either send you the vid to hear it or listen to it from the phone. Daryl

Did you replace the alternator yet?

Yes I did already. Seems to be coming from inside the engine. Idk what to do.

ok i got braveand ran the car for a bit without accessory belt and guess what, i didnt hear the noise anymore

Idler pulley? Tensioner pulley? It's EXTREMELY COMMON for those to frag. Start spinning them by hand and see if any of them feel nasty.

Car doesnt make the noise with accessory belt off, put it back on and it makes the noise, which leads me to believe that its either the waterpump or powersteering pump, I spun waterpump and powersteering pump, powersteering pump doesnt spin as freely as the waterpump, in fsct when I try to whirl it fast it hardly stays spinning.mive already changed alternater and tensioner pulley. Oddly powersteeringnpump doesnt make that other noise that im use to hearing usually on some fords, when powersteering pump is going lol

Ah...you said ACCESSORY belt lol.