Alternator Options

[Slideways]

Just looking at the available Valeo parts myself as mine is struggling to break into the 13V range. The Bimmerworld page claims they are selling the brand new Valeo unit, but the part # they list suggests it's a reman. I've had bad luck with Rock Auto parts in the past.

The voltage regulator wears out over time and might be causing the low voltage. They should be less than 100 bucks.

[nahvkolaj]

Fantastic info! Thank you!

I just confirmed on the Valeo link you provided. Interesting that the Bimmerworld part number is actually a Re-Gen and the unit from Rock Auto is an Origins and cheaper.

Just looking at the available Valeo parts myself as mine is struggling to break into the 13V range. The Bimmerworld page claims they are selling the brand new Valeo unit, but the part # they list suggests it's a reman. I've had bad luck with Rock Auto parts in the past.

[ARCHBID]

The issue with the reman Bosch units is they licensed the business to a Chinese firm that substituted shit Chinese components, notably the bearings. New Bosch has quality bearings.

Valeo is OE and great, though most times you don't need an alternator, just a voltage regulator.

[whoissuprme]

Thank you, already on the way

Good to hear! Sorry about the late response I haven't been active on the forums lately.

[0-60motorsports]

I've been running this alternator since October with absolutely 0 issues. Go with the x5 alternator if you need a replacement

Thank you, already on the way

[whoissuprme]

Any updates?

I've been running this alternator since October with absolutely 0 issues. Go with the x5 alternator if you need a replacement

[bigjae46]

On a side note, why are people interested in using any other alternator than the one specifically made for the e46 M3? What are the advantages?

Availability and cost. For me, I keep and rotate cheap spares for track use. I wouldn't mind rotating old X5 alternators through my spare parts bin.

[Subfra///Me]

Bought a Valeo alt in December on Bimmerworld when it was on sale. Installed it last week when my Bosch alt voltage regulator started to fail causing some electrical gremlins to pop up in the car. The Valeo alt started whining as soon as I pulled out of my shops parking lot. My car sounded supercharged...

Purchasing an OEM BMW alternator through my shop and having them install it again. I get a 2 year warranty on the alternator and don't have to pay for labor again. It seems like Valeo and Bosch reman alternators are super hit or miss and it's the luck of the draw you'll get one that works. Paying the OEM tax and going the BMW route with this part.

As I said before, I went thru two genuine BMW alternators in about 10k miles, so I'm not sure they are any better. They do have a limited lifetime warranty that extends beyond the typical two year warranty, but you have to pay for the labor though. Unless you have some sort of connections.

On a side note, why are people interested in using any other alternator than the one specifically made for the e46 M3? What are the advantages?

[bigjae46]

Funny enough, the M3 has a molded intake port on the brake duct that has been blocked off. That could have been for alternator ducting.

That’s exactly what it’s for.

I was thinking about running. 200amp HO alternator in my 330ci to power a massive 25wattsx2 amp that was 44” long. Yup…that amp had unregulated power supplies and was stable to a 1/4 ohm. Almost a short circuit! But I would have needed cooling to run that alternator.


Ultimately I decided to go with more efficient amps.

[0-60motorsports]

A lot of the non-M guys have used the BSD alternators on their pre-BSD cars with seemingly no ill effect. I don't know if those voltage regulators just fall back to the old school mode or what.

Thanks for that info. I just didn't want to risk getting it then it'll be a paper weight if it didn't work right. I want it to have oe functionality etc with the battery light etc on the dash coming in when it's supposed to come on. I tried tors with an e92 voltage regulator and same thing, if anything is wrong I won't know as the battery light on the dash will not come on..

[terra]

I just heard from my tech and he said it'll fit but the plug functionality will not work as it uses BSD communication. So it's better we stick to the 140Amp. I really wanted to get the Z4M alternator lol

A lot of the non-M guys have used the BSD alternators on their pre-BSD cars with seemingly no ill effect. I don’t know if those voltage regulators just fall back to the old school mode or what.

[0-60motorsports]

Yes, I'd only go with an E46 alternator. I thought the Z4M one could be used in a pinch due to the mounting points being the same but forgot about the BSD functionality.

Yeah I'll order the X5 140Amp alternator as there is no harm using a stronger alternator as shown on the Z4M. Thanks.

[Slideways]

I just heard from my tech and he said it'll fit but the plug functionality will not work as it uses BSD communication. So it's better we stick to the 140Amp. I really wanted to get the Z4M alternator lol

Yes, I'd only go with an E46 alternator. I thought the Z4M one could be used in a pinch due to the mounting points being the same but forgot about the BSD functionality.

[0-60motorsports]

It will as the mount on the S54 is the same for both cars. Z4M is 150A while the E46 is 120A.

I just heard from my tech and he said it'll fit but the plug functionality will not work as it uses BSD communication. So it's better we stick to the 140Amp. I really wanted to get the Z4M alternator lol

[AWE46M3]

Bought a Valeo alt in December on Bimmerworld when it was on sale. Installed it last week when my Bosch alt voltage regulator started to fail causing some electrical gremlins to pop up in the car. The Valeo alt started whining as soon as I pulled out of my shops parking lot. My car sounded supercharged...

Purchasing an OEM BMW alternator through my shop and having them install it again. I get a 2 year warranty on the alternator and don't have to pay for labor again. It seems like Valeo and Bosch reman alternators are super hit or miss and it's the luck of the draw you'll get one that works. Paying the OEM tax and going the BMW route with this part.