Alternator Options

[Slideways]

Anyone know if the Z4M alternator will fit on our M3's? Especially the electrical connector( I guess if we change the back cover)?

The mount is the same for both cars, but the Z4M is 150A while the E46 is 120A.

Edit: Z4M also has a different connector due to BSD comms.

[0-60motorsports]

Anyone know if the Z4M alternator will fit on our M3's? Especially the electrical connector( I guess if we change the back cover)?

[ZiMMie]

The problem might be the oil cooler lines it might interfere with the duction maybe not.

[terra]

...That might actually be that mystery solved. I always wondered what that was for. Sure looks like the alternator ducting would fit there

[Slideways]

It's clearly there for making your own DIY brake ducts

For only the driver's side? lol

[heinzboehmer]

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.

It's clearly there for making your own DIY brake ducts

[Slideways]

ok, I think some non-Ms had a cooling duct from the foglight area. Might have been ZHPs or something. Or maybe auto cars.

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.

[bigjae46]

No need to swap the regulator as they are the same.

The back housing is different (the plastic piece). On the non m there is someone sort of intake for venting for cooling whiles the M doesn't have it.

ok, I think some non-Ms had a cooling duct from the foglight area. Might have been ZHPs or something. Or maybe auto cars.

[ZiMMie]

So a non-M alternator bolts right up? Just need to swap the regulator?

No need to swap the regulator as they are the same.

The back housing is different (the plastic piece). On the non m there is someone sort of intake for venting for cooling whiles the M doesn't have it.

[tlow98]

So a non-M alternator bolts right up? Just need to swap the regulator?

I test fitted my 330i alternator when the motor was out. Valeo unit with the correct connector on the back. Fit perfect.

how they differ, I do not know. Kept it as a spare.

[bigjae46]

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.

So a non-M alternator bolts right up? Just need to swap the regulator?

[Subfra///Me]

I doubt they would warranty it unless they installed it. Maybe they would if it is out of the car, but good luck making that argument. Rock auto should deliver the OEM Valeo unit just like the other online stores.

They did replace it the last time. Two weeks prior to that I bought a genuine BMW alternator from them and did it myself. That one was a dud. Don't have much confidence in their part, so I'm just going to get the Valeo from Rock Auto and do it myself. Probably cheaper in the long run and much less hassle.

Also, didn't like how they told me it was purchased more than two years ago so the warranty expired. When I asked them about the limited lifetime warranty on alternators, they changed their tune and said it may be covered if I brought it in for diagnostics. No thanks. Just going to diy with a better part.

[Slideways]

Going to pull the trigger on the Valeo Origins alternator from Rock Auto.

I'm a little frustrated two genuine BMW (Bosch) alternators have had issues within 10k miles. Genuine BMW alternators from the dealer are one of a few parts supposedly covered by a limited lifetime warranty that exceeds the normal two year original BMW parts warranty. However, I could either spend $240 and replace it myself with a likely more reliable unit or wait for the bearing to fail completely, tow it to BMW, hope they honor the limited lifetime warranty and then have to pay them to install the new one as labor isn't covered. Taking it there now with the bearing making noise, but the alternator otherwise functioning, is unlikely to result in a new alternator and I would have to pay the diagnostic fee even if they reject the claim. Not really worth the hassle.

I doubt they would warranty it unless they installed it. Maybe they would if it is out of the car, but good luck making that argument. Rock auto should deliver the OEM Valeo unit just like the other online stores.

[Subfra///Me]

Going to pull the trigger on the Valeo Origins alternator from Rock Auto.

I'm a little frustrated two genuine BMW (Bosch) alternators have had issues within 10k miles. Genuine BMW alternators from the dealer are one of a few parts supposedly covered by a limited lifetime warranty that exceeds the normal two year original BMW parts warranty. However, I could either spend $240 and replace it myself with a likely more reliable unit or wait for the bearing to fail completely, tow it to BMW, hope they honor the limited lifetime warranty and then have to pay them to install the new one as labor isn't covered. Taking it there now with the bearing making noise, but the alternator otherwise functioning, is unlikely to result in a new alternator and I would have to pay the diagnostic fee even if they reject the claim. Not really worth the hassle.

[BlueBimmers]

Great info, and great reminder to check Rock Auto when buying expensive parts. I found an expansion tank for my M5 way below usual price.