Bosch alternators - thoughts on current batch?

[Nate047]

Hey guys, so I have one of the Bosch remanufactured alternators from a few years ago that came from a known batch of bad units. In fact, I had one, it went bad, I had it replaced from FCP, and now the replacement is bad. SO... I was wondering if anyone has some more recent experience with Bosch remanufactured alternators, are we still avoiding these?

The issues spanned across E46 M3, E36 M3, I think numerous other models and maybe even across the board with Bosch. My go to shop told me they were avoiding them entirely for all cars, but that was some time ago.

I'm just wondering if this has been resolved or if these are still problematic?

[ChapterM3]

I threw in a Bosch in 2020 in mine, haven't had an issue - just threw the same reman in my e60 5 series and no issues as well - maybe I totally missed that bad batch bulletin? When was that bad batch made?

[Nate047]

I threw in a Bosch in 2020 in mine, haven't had an issue - just threw the same reman in my e60 5 series and no issues as well - maybe I totally missed that bad batch bulletin? When was that bad batch made?

I don't think it was officially announced, but rather it was talked about on here a good amount, I had the problem, I know of a few people who had problems on other cars, my shop guys steer clear of them entirely now, etc...

[Altaran]

If you're getting a new unit, you can buy Valeo. That's what I got. It was also an OEM supplier for our cars.

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[BTB]

Had my (2nd?) Bosch remanned unit go bad in 2021. No idea if anything's changed but why not just get Valeo? Been running one since

[Nate047]

Only reason is because of the lifetime replacement from FCP, unfortunately they won’t let you credit towards a different item in a situation like this.

[bigjae46]

Replace the voltage regulator!!!

[Obioban]

Bosch moved a lot of production to China, and a lot of their parts have become crap as a result.

Get a Valeo.

[Slideways]

Replace the voltage regulator!!!

My guess was also the voltage regulator. If Bosch is cheaping out on the voltage regulator or not replacing it, that could be why these remanufactured units by Bosch are failing. The Valeo voltage regulator is about 80-100 bucks on its own and looks to be made by Temic (manufacturer of the oil level sensor on newer models).

To my knowledge, the common things that wear out on these E46 alternators are the voltage regulator and the bearings, both of which can be purchased to refurbish a unit. These alternators are a pretty simple devices and should last quite a long time.

[PetrolM3]

Several months ago, I got a brand new (not rebuilt) Bosch for my non-M and it was bad - whining noise right off the start. Returned it and fixed my 20 year old unit (replaced voltage regulator) instead.

[lemoose]

My reman bosch lasted about 40k miles before the bearing gave out and started grinding itself and spitting out shavings. I replaced it last week and was in between getting another reman through FCP lifetime replacement, but ended up getting a valeo. For the premium, I reckon the valeo should last at least 3 times as long, and I also feel better about not putting garbage in my car.

[bigjae46]

My guess was also the voltage regulator. If Bosch is cheaping out on the voltage regulator or not replacing it, that could be why these remanufactured units by Bosch are failing. The Valeo voltage regulator is about 80-100 bucks on its own and looks to be made by Temic (manufacturer of the oil level sensor on newer models).

To my knowledge, the common things that wear out on these E46 alternators are the voltage regulator and the bearings, both of which can be purchased to refurbish a unit. These alternators are a pretty simple devices and should last quite a long time.

They don't replace the regulator when its rebuilt. Not sure why. I still prefer the Valeo rebuild if you can get one...still need to replace the regulator when you get it. I'd also clean up the stator. I'm guessing Bosch doesn't even remove the regulator. It doesn't go back on once its removed. The brushes engage and can't be reset without a lot of prying on thin plastic. I'd guess that you can replace the bearings and clean the windings without removing it.

I'd rather rebuild one myself if I could find the bearings. Get them REM polished and should last a really long time. Its like the starter. Lots of people replace the starter when its the solenoid that goes bad. It's easy to disassemble, clean, and reassemble the motor. I'd only toss the starter if the gear teeth were chewed up.

I still think the best option is a BMW reman if it has to be reliable. Limited lifetime warranty - part is covered - and I think it is less likely to have an issue. I use a Bosch reman because I'm cheap and it's a track car.

[Nate047]

FWIW Rockauto has Valeo units marked as new, not reman, for about $225.

[lemoose]

FWIW Rockauto has Valeo units marked as new, not reman, for about $225.

Damn i spent over $100 more at bimmerworld lol

[Slideways]

Thought I would link the thread on rebuilding the Valeo alternator - https://forums.m3cutters.co.uk/threa...-e46-m3.42304/

Voltage regulator + 2 bearings is ~$100