Is my alternator giving out?

[ThirdeYe]

Lately i've been noticing a faint whining noise coming from the alternator, under my hood (not through the speakers). My battery reads fine (12V) and measures over 500 CCA and it's a fairly new Acura brand battery. I've also been noticing that whenever I touch the gas pedal, I get a loud brushing noise coming from the alternator or somewhere near it. I had an alternator go bad on one of my other cars and I remember it would make a whining/brushing noise whenever I accelerate, then go away instantly after I let off the pedal and coast (which is what my car's doing now). I'm gonna have it checked out tomorrow, but does anyone happen to know if this is a symptom of alternator troubles? Oh yeah, one other thing I noticed recently is if I turn my headlights on and off, the engine RPMs fluxuate and the car kind of bogs for a second. When I purchased the car, it already had a Pioneer CD player installed and 2 subs in the trunk with what I believe is a Scosche amp connected to the back of the sub housing. It's always been making this brushing noise, since i've had the car. Any ideas? I don't know if it's related to the alternator or perhaps grounding with the stereo, etc. I'm not too familiar with the schematics of stereo stuff in cars, i've just had other people put them in for me.

 

[Quest]

ThirdeYe-

-what is the battery reading after you started up your car from cold?

-has this rpm-dependent whine been with this car since day-1?

Q.

 

[dwendt44]

If the bearings or bushings are going bad, they could whine even though the electrical output is good.
Over tightened belt, if adjustable, could cause it too.

 

[Mr_Accord]

That definately sounds like it could either the bearings are going on your alternator or the belt isn't ajusted properly. Check to see if the belt is too tight, if thats the case running your alternator with a belt thats over tightened can also wear down the bearings on the alternator alot faster than expected, yet still have good electricity output.

 

[ThirdeYe]

I had it checked today and they didn't even look at the alternator -rolls eyes at the shop- I saw what they did, they simply measured my battery when the car was running, and said "It's charging fine" and when I mentioned the noises, he simply said it was probably my motor -laughs- I know another person that did alternator work on my old car and did a great job, so i'm gonna see if he can take a look at it. I remember when my alternator was making crazy noises in my last car, they tested it and said it was fine. Right, so the alternator's supposed to sound like a turbo kit? Had it rebuilt and it sounded great and worked great again.

Quest - I purchased the car 2 months ago and it's been doing it since I purchased it. The cold battery readout was 12V.

I wonder if using that cleaning spray would help in this situation, if it turns out the belt isn't overtightened?

 

[Quest]

ThirdeYe-
No, what I want to know is that shortly after you started up the engine after sitting overnite (the engine is actually running), what's the reading off of your battery post?

I don't want/care any static readings straight off your battery (engine not running/alternator not running), if you know what I mean.

Also: has that "whining" sound been around since you got that car (is it coming from your speakers or from under the hood?)

 

[kgb007stb]

122k miles on an alternator is decent mileage. I have build and re-build alternators for fun so I got quite some experience when it comes this. The whining noise will probably be a bearing or brushes, in either case have it checked out so that you are not left stranded somewhere. I had a similar symptom in one of my rides, gradually that whining sound became louder to the point where I could hear a loud metal to metal noise. When I took it apart all of the grease from the bearing housing seeped out, it had no lubrication, hence the reason why I had the metal to metal grinding.

Have your alternator expert look at it, if he is trustworthy he should be able to tell you what needs to happen to restore that alternator to original working condition. I do not buy mine from the regular stores any more after a family member went through 3 rebuild alternators in three weeks. I now have a policy to only buy 100% brand new, the internet has some great prices.

Many ask for the age of the alternator, that all depends on your driving conditions. Dust conditions will act like sand on the brushes wearing them down, the position in the engine bay will determine the life of the wiring. Alternators that cannot get proper cooling will go sooner than those with adequate cooling.

 

[ThirdeYe]

Quote:

---

ThirdeYe-
No, what I want to know is that shortly after you started up the engine after sitting overnite (the engine is actually running), what's the reading off of your battery post?

I don't want/care any static readings straight off your battery (engine not running/alternator not running), if you know what I mean.

Also: has that "whining" sound been around since you got that car (is it coming from your speakers or from under the hood?)

---

The battery read 12V from the reader my uncle let me use while the battery was cold and car wasn't on. I don't know what it reads when the car's on, but the shop checked it this morning and said it was fine. The whining has been there since I got the car, and it's coming from under the hood, but it's more of a brushing/flapping noise. The battery was just tested at the Acura dealership a few weeks ago and it read over 500CCA according to their test (if that helps with anything). I just had a good mechanic look at it and said nothing was wrong with it. It charges fine, the belt's properly tight, and doesn't appear to be anything wrong with any of it. I wonder where the noise is coming from then? or maybe it's just normal and i'm crazy? The acura dealership also checked my timing belt and didn't see anything wrong with it. What noises from the engine (B18) could be making a brushing/flapping noise? It's odd how it goes away after I let off the gas, and it's only really prevalent while i'm accelerating.

 

[ThirdeYe]

I wonder if perhaps it's the transmission? It doesn't shift hard or anything, but no one can find a problem with my alternator and it only does it when I accelerate... Does anyone happen to know the symptoms of what's happening me relating to a transmission problem?

 

[ewetho]

12.45 Volts DC is a 75% charge
12.65 is 100%

Could you have an exhaust leak down at the flex pipe?

 

[ThirdeYe]

I'm not sure, is there a way I can check?

 

[Quest]

ThirdeYe-
Your battery post voltage reading (DC) shall read in excess of 12V after the engine starts, and it shall be somewhere between 13.6V ~14.5VDC, depending on the ambient temperature and the battery's state of discharge (or battery health).

Borrow a voltmeter and then start your engine and take a reading first thing in the morning after a nice, cool nite's rest. Take the reading immediately after you start your engine and then also 1 more reading after running for 1/2 hr (all readings come off of your battery post's +ve and -ve).

Q.

 

[deepsquat]

I am with Quest...should read higher then 12...need over 13 ...just to charge the battery ...though you still don't know if it is a faulty battery or alternator....have it checked at a Shucks or some such auto parts store

 

[ChromiumSteel]

If you do get stranded somewhere, take a piece of wood and a hammer and give the alternator one or two good hits. It will get you about two weeks out of the alt. I learned this from the guys at J&S alternator and starter supply while they were rebuilding an alt on a Civic. I once used it for a kid at a gas station when his Honda wouldn't start. He looks at me and says "Your one #@$%! of a mechanic!" I didn't tell him where I learned that trick!

 

[ThirdeYe]

I had it checked this morning right around the block from me at a battery/alternator shop, the car wasn't fully warm when I got there and he checked it while it was running. He said it was charging fine, and the other mechanic that rebuilt the alternator in my old car said it was fine as well, and the belt was on fine. I still have no idea what it is. I noticed that it seems to go away a little bit after the car warms up some, but it's still there whenever I accelerate. I have no clue what the noise is, but perhaps it's normal for an Integra to make some sort of tapping/brushing noise? I wouldn't think so though. I was thinking that it either had something to do with the transmission, fuel injectors, or the valves. Any thoughts on those?

 

[Quest]

ThirdeYe-

Follow my drift and get the readings first. No need to make any hunch or listen to those shop guys for now.

Unless it's been abused, generally, Japanese made alternators are extremely durable/reliable to begin with (Denso, Mitsubishi, Hitachi) for they are well-respected in the electrical motor industry.

Disregard the "whining" sound first and focus on getting the voltage reading to us (or PM me if you like). We then go from there....

Focus is the key word..

Q.

 

[mazduh30]

What is near your Alt? Power steering pump or tensioner (if you have a serpentine belt)? Slipping belt?

 

[ThirdeYe]

The power steering is next to it, but I just flushed that a couple weeks ago and seems fine. I'll try to see if I can get my uncle to let me borrow that voltage reader again and measure it while it's running.

 

[Quest]

When you flush your power steering reservoir, did you replace it with HOnda PS fluid (or aftermarket Honda approved PS fluid) using turkey baster method?

...waiting for your alternator voltage reading.

Q.

 

[ThirdeYe]

Genuine Honda PS fluid using turkey baster. I just took the car around the block and tried to make a recording of outside the car and inside the car, moving and stationary, but it didn't turn out so well with my headset, but I have another microphone that doesn't have noise-cancellation so it might work better. I'm starting to think that the slight whine/rubbing noise i'm hearing might be normal, but i'll get that voltage reader soon. Do you happen to know how much they would cost if I wanted to just buy one? Or what kind I should get? I feel kind of awkward asking my uncle to borrow it again, after I just did 2 days ago.