Alternator Options

[Subfra///Me]

New alternator time here as well. Original lasted 84,000 miles. I bought a genuine BMW alternator from the dealer (Bosch) and installed it myself. It was faulty and BMW replaced with another genuine part, which has only been in for about 10,000 miles and now the bearing is making noise. I tried the link shared above, but the Valeo unit appears to be discontinued or unavailable from FCP. The best prices I have seen are from Bimmerworld and Rock Auto. The part number varies slightly on Rock Auto, but it says it's interchangeable. Rock Auto is $60 cheaper, so if it's essentially the same part, I'd like to save the money, but ultimately, I want to make sure I'm comparing apples to apples. Anyone have experience with the Valeo from Rock Auto or know if it's actually the same/correct part? Bimmerworld lists the Valeo as 12317831436 (437320). Rock Auto says OEM/Interchange Numbers: 12317830791, 12317831436 and (439317).

[0-60motorsports]

its a 55mm diameter pulley same with any M/S 5x motor..

as for the alternator, any m54 alternator should work if you switch the back cover.

I ran a 90amp(less drag) version in my E36/S54. For an e46 120amp+ unless you have A/C,radio etc. electronics deleted.

Thanks for the feedback. I am not sure whether to stick to the 120amp or go to a 140/150Amp alternator. In our summer with the AC blowing and 125F+ plus high humidity the aux fan running at full speed the 140/150 Alternator might be a better choice?

Then again never had issues with my original alternator until now, the battery monitor today shows its making 12V instead of a Minimum of 13V up to 14V+. I am sure the alternator is on the way out.

[ZiMMie]

Any updates?

its a 55mm diameter pulley same with any M/S 5x motor..

as for the alternator, any m54 alternator should work if you switch the back cover.

I ran a 90amp(less drag) version in my E36/S54. For an e46 120amp+ unless you have A/C,radio etc. electronics deleted.

[0-60motorsports]

I was away for a little bit and the car is still at my buddies shop. I will be going there tomorrow (10/13/22) and will take measurements on the pulley diameter to make sure it's the same. While I was swapping in the new alternator I decided to swap out all the pulleys with new ones and do a belt service and a new clutch fan. Stay tuned for more info. I'll report back with my findings!

Any updates?

[bigjae46]

FCP probably not liking the price or contract terms they can get for them to allow them to warranty.

I often wondered if FCP returns the warrantied items back to the manufacturer. If not where do they go?


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I’m sure they do whenever they can.

Id be inclined to buy a BMW reman from the dealer. Limited lifetime warranty.

If the dealer installs a BMW part and the customer pays something then there is a 2 year parts and labor warranty.

BMW provides a limited lifetime warranty on specific parts - IIRC, it’s alternator, water pump, starters, ac compressors, shocks and struts. Might be a few other things. This warranty covers the part only.

Talk to you dealer first but you’d need to show the failure. Typically a screen shot of the fault code works, just depends.

I’m thinking about getting an OE alternator and keep my Bosch as a spare.

[eacmen]

PSA: Just got notified that Bimmerworld has the Valeo units back in stock if anyone is looking for one:

https://www.bimmerworld.com/Engine/Alternators/Alternator-120-Amp-12-31-7-831-436_2.html

[eacmen]

FCP probably not liking the price or contract terms they can get for them to allow them to warranty.

I often wondered if FCP returns the warrantied items back to the manufacturer. If not where do they go?


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[mrgizmo04]

FCP going downhill

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[bmwfnatic]

According to FCP the M3/Z3 Valeo are discontinued. Shocking ! It is too early for these things to happen. There are still plenty of these cars on the road.

I bought one here in Europe last week, was freshly made, not some old stock. Pretty sure FCP is just wrong.

[0-60motorsports]

There are plenty of them online in stock around the world. No need to worry. Im sure they'll be back i stock at FCP sooner or later.

[eacmen]

According to FCP the M3/Z3 Valeo are discontinued. Shocking ! It is too early for these things to happen. There are still plenty of these cars on the road.

I got mine from Bimmerworld: https://www.bimmerworld.com/Alternat...831-436_2.html

They were out of stock then came back in stock recently. Maybe its discontinued just at FCP?

[Maxima SE]

According to FCP the M3/Z3 Valeo are discontinued. Shocking ! It is too early for these things to happen. There are still plenty of these cars on the road.

[Tbonem3]

I think the bosch alts, in my own experience and seeing others', either are bad pretty much immediately, or you get a good one that lasts. It took me 2 duds initially, but my 3rd bosch reman has also lasted me the last 5 years or so.

[Amos]

So just to add a data point:

My original alternator died at 195k km.

I guess I didn't do my research at the time because I went with a Bosch reman from FCP Euro but it's still running fine 5 years and 20k km later. Time will tell I guess.

[Maxima SE]

A multimeter won't really give enough detail for show a bad diode. Basically it can be detected by looking at the ripple on the output which will be what the tester is looking at. Cheap battery testers often can do a ripple test.

If you put the meter on AC volts, what do you get?

I took it back to autozone today and had them connect the tester to the battery directly. Both battery and alternator came back good.