BROCKES300

I recently replaced my original Es300 alternator that had 290,000k with an original alternator from a 2004 Avalon with 123,000k. That fixed the whine for the most part. When the car is in Park or neutral, the engine is nearly silent, then when shifted in reverse or drive the alternator begins to whine. The noise is worse when cold, and after about an hour of driving the whine fades. I know it's the alternator, because I listened too it with a long screw driver. This newer alternator also seems to work just fine, power wise (stopped flickering, dimming headlights...). Any ideas on my next steps?

​​​​Thanks in advance!

Arsenii

Hello,

Can you record the sound that your alternator makes?
If you have a "closed loop", like the belt that is wrapped around a bunch of pulleys, chances are that the noise will distribute across other pulleys, meaning that this noise may not necessarily come from the alternator.
It really seems like a belt, since the alternator has the rotor as an electromagnet, meaning that is the more battery is discharged, the more load it will put on the alternator, making the alternator work harder, thereby making the belt slip. At least that's my theory..

Hope this helps and best of luck!

Richardsr

My first thought was also belt or belt tension and simply putting the car in gear doesn’t create a big jump in electrical engine requirements. The engine load of an alternator is negligible and there’s a formula for figuring out what the bhp requirements are.

14v times 130A max output = 1820 watts. 1820/746(watt to horsepower) = 2.43hp.

But I’m also confused because the OP physically hears the noise with the old screwdriver test. I used a half inch wooden dowel for decades before breaking down and getting a stethoscope for isolating noise. And hey... an alternator with 130K on it isn’t exactly new.

BROCKES300

Thank you for your informative replies! Here is a sample video of the sound, from the driver's seat with the driver's door open. I just bought a new belt for that series of pulleys (couldn't hurt). If that doesn't fix the problem, I will just live with it. As Richardsr pointed out, it does have 130k under it's belt.

My logic was.. Mine was 4 years older and had 160k miles more on it before it started making noise and not charging correctly. So I went to my local pick and pull on a Saturday and found this mint, rear ended, otherwise well taken care of Avalon with 130k, and took the alternator, which was only $23.99 with a 13 month warranty. I will either return it and get a Denso reman from Rockauto, or wait 12 months and then get the reman...

Anyways, Thank you!

LeX2K

That's bearing whine for sure only question is the source.

BROCKES300

Thanks!

I guess maybe I should do further troubleshooting, maybe even buckle down and buy a stethoscope

Richardsr

Yeah, $20 will get you a great stethoscope and they’re unbeatable for locating engine noises.

I agree with L2K about the bearing noise. Classic. But... changing the belt can’t hurt since it’s how old now?

And what year is your car, btw?

BROCKES300

its a 2000

Richardsr

After re-reading this thread... When is the last time you checked your power steering fluid. The only device that causes this sound in gear and not Park is the Power Steering Pump and it’s probably low on fluid. The Power Steering Pump is the only component on the serpentine belt that demands more grip when in gear vs not in gear. And if it’s dry, it get’s angry.

In the OP you said the whine was there before and after changing your alternator. So, it may not be your alternator but rather a Power Steering Pump instead, or low on fluid.

BROCKES300

I tried what everyone suggested. The problem was not just the alternator! It turns out it was a combination of a few things. The alternator, power-steering pump, and transmission. I changed the alternator belt, alternator sound went away. Checked power-steering fluid... it was a bit low and it was just generic power-steering fluid, which the previous owner put in there. Put some Dexron-III in there, whine went away and steering is a bit better. However, some of the whine was still there in drive.... So I checked again, and it was coming from the tranny. so I dropped the pan and changed the filter. Now I have a 300,000k mile 2000 ES 300 that softly shifts into all gears before 2k rpm and feels like new mechanically.

Now onto the Struts!

Thanks again everyone!

acarapella

If it’s right after an alternator change, my bet is belt is too tight. As a rule, I always say I shouldn’t be able to twist the longest belt distance between pulleys a full 180° or push it an inch. Shouldn’t be able to do either. Too loose squeaks too tight whines

Richardsr

Glad to see your problem is gone.

If you want to be really thorough with the power steering, siphon out the ps fluid and replace with new fluid. Do this again every 6 months. Beats removing hoses and will ensure your ps pump longevity.

acarapella

I always liked to hook the return line to a double bath and long clear hose (plumbing section of the local home improvement store) into a container with the front jacked up, turn the where lock to lock several times WHILE KEEPING THE RESERVOIR FULL of new fluid, and eventually new fluid will start to come out into the container. That’s a full flush.

Warning: don’t let the clear hose go into the fluid in the waste container. My Lexus never sucked fluid back in, but my wife’s Honda minivan did, and as some of you may know, Honda’s are incompatible with regular steering fluid (atf) and I had to flush it 6 times to stop the foaming

BROCKES300

I guess I should have specified, I did do a flush. I didn't just add fluid.

acarapella

Good! So your car is back to 100%?