Last week my 03 with 168K miles started to have some "eee" noise under the hood, it sounds like an EV motor noise to me. It went away and back yesterday. In rush area traffic yesterday, the radio suddenly stopped, dash backlight was on and off. Everything came back after a min. Then more some warning light showed on the dash, my driver side window stopped working and my car was not able to keep idle. I decided to exit and pulled into a parking lot at the church. Turn off the engine and car wouldn't start.
I managed to remove the battery and took it home, it was low. Charged it overnight, put it back on, car runs ok. I have a feeling my alternator is the issue. Any input?
If I need to replace it with Toyota part, anyone know the correct part number? I know there are many remanufactured unit but I want to get "NEW" one instead.

 

I had alternator replaced two years ago around 150k miles on car. Horrible grating noise that made me think my engine was coming apart. Not just a squeal, like grating metal. I really thought that was it for my engine, out of nowhere. Then 20 seconds later all was fine. Ignored it (life...), but 2 weeks later car hesitated on road, got harder to keep running. Dash lights out, eventually car stalled and could not move. . Had to get it towed. Only time ever. Not obvious but I suspected alternator. Anyway I brought it to a Firestone franchise because (1) they were open on Sunday and (2) I didn't want car towed to Lexus dealer. Too far. FWIW, it was alternator. Claimed battery was fine despite that. I got a reman'd alternator (I assume), it has been fine for 10000 miles or so. In contrast, when my starter went bad (possibly due to overcranking on a bad battery) I could still start the car just with bad grinding (bad solenoid?), so I got it to dealer. Similar with water pump. I saw temp gauge spike and a/c stop working. Cooled down car for 1/2 hour before it got to mega-hot, then drove (!) 2 miles to local mechanic. I prefer dealer but I've been OK with non-OEM parts where needed/convenient. (Supposedly water pump had been done 30000 miles earlier with timing belt, but I have a feelin they cheated me). Luckily it happened when I was close to home. The audible radiator fans running non-stop should have clued me in the day before.

Ironically, my parent 'ES350 alternator went out while they were visiting me, around a year later, also at around 150k miles. More classic symptoms: charge light went on, they called AAA who tested and sad it was not battery, but alternator. I also took them to a Firestone since it was Sunday. It cost nearly double what mine did, and I got several quotes. I think it is more labor-intensive and book-hours == $$. One time an LS was cheaper! (No timing belt to replace on their ES, etc.)

Anyway, I know non-OEM parts can be risky, especially for sensors (MAF, O2, etc.) but I have been fine so far in few cases where I had a fairly important component replaced non-OE by a place that knows where to source decent parts. With the water pump, I could actually here the difference as the new one kind of had a sound to it. But I either got used to it or it diminished.

My other car is approaching 100k miles and it makes me wonder if I should replace water pump or alternator pro-actively. It has no timing belt so no "natural time" to do the water pump.

Good luck. Don't leave it!

 

https://www.amayama.com/en/part/toyota/2706050280

when the part number has 84 added to the end, its a reman
27060-50280-84

 

You won't find a new one unless you choose to spend over a grand from one of the Japanese suppliers as fortitude posted above.
Lexus dealers only sell a reman product but it's a Denso which is the best you'll find for your car. Fortunately, you can also buy it from RockAuto for a lot less money.
@Yamae has posted previously how Denso has stricter reman criteria than other manufacturers. I don't want to speak for him maybe he will chime in with more info...

 

There are many Denso alternators re-manufactured by non Denso companies. I make it a rule not to use those. The reason is very simple. You can't expect a lot. Both the quality and the reliability are not good. Those non Denso companies use non Denso parts. I'd say most of those parts are kind of counterfeits. Denso's genuine parts are rather expensive but those are very well made. For examples voltage regulators alone cost more than $100. On the other hand, non Denso voltage regulators cost less than 1/3. You get what you pay for.

My local shops or dealers often request me to help having strange electric or electronic related problems. Some of those were related to alternators that were re-manufactured by non Denso companies. For an example, there came in a car which showed that the battery was not very well charged but the charging voltage at 1500rpm was 14.4V. At the idle, it's only 12.5V, I found. The alternator had a non Denso voltage regulator inside. Changing it using a genuine Denso's regulator, the problem was solved. the voltage showed 14.2V at the idle. I found that the non Denso regulator could not pass trough the enough current to rotating coils due to the higher internal resistance of the driving semiconductor.

It is smarter to use a genuine Denso alternator or a re-manufactured one by Denso.

 

How can you make sure it's a Denso alternator remanufactured with Denso parts? Buy from Denso or a dealer?

 

Excellent question

 

I have a Denso reman from Rock Auto waiting to go in my car. At that point, I will have the original rebuilt by a local place and just keep it as a spare and forgo the core fee. Thankfully for my GX460, I was able to get a brand new Denso alternator for $400 from Bell Lexus when I replaced it last year. The one in my LS is still working fine but at this age, I'm ok with replacing it before it fails.

 

I feel like the only option is to get remanufactured alternator. My next step is to remove it from my LS, then exam it and see if there is anyway to fix it. In parallel, I probably will get one from the dealer (not knowing how much at the moment).

 

Go here click where to buy
https://www.densoautoparts.com/alternators/

 

Rock Auto does not have a Denso Alternator listed for an 01--3 LS430.

 

Interesting.
My fault, the link I have saved for RA takes me straight to 2006 parts.
The Lexus part number is different for the earlier 430's.
IIRC it's the same alternator but the electrical connector is different.

A 2001 to 2003 alternator from Bell Lexus is currently $211.47 (plus core charge) which is approx $85 more than a 04 to 06 Denso from RA.

 

Denso part number is 210-1054
Currently listed as out of stock at Rock Auto

Via a denso distributor = $237
https://www.densoproducts.com/denso-...efv=2451128331

Current MyLParts price = $205 (+core). 27060-50280-84. add PROMO CODE. CL5 at check out to receive 10%off
https://www.mylparts.com/oem-parts/l...Y4LWdhcw%3D%3D

 

On Advance Auto site for Carquest in rebuild it states using OEM parts.

 

For my old Taurus and Civic, I will consider using Advance/AutoZone... but for my LS, I will keep using Toyota parts