Correct alternator

[jprottas]

Which is the correct Alternator? Bimmerworld says valeo can only replace valeo. But bosch was suggested to me. What's the "compact" decription mean? If there's a benefit to stepping up to a 140 I'd like to do that. It's a 1999 m3 convertible with aftermarket stereo.. And what corresponding parts do i need...tensioner (there seem to be 2 really different styles) Vin WBSBK033XXEC41033
Thank You

Sent from my SM-N950U using Tapatalk

[realjones]

Stock 80a alternator is 12311744565. If you want a 140a you need a 55mm pulley (might be the same as your current alternator). Seems like some are direct fit and some need a longer mounting bolt.

[Braymond141]

140amp is stock for Convertibles. Your top/electrical accessories will struggle using the 80amp. Stick with the standard equipment 140amp. 140amp is not an upgrade if you do not have a convertible. More engine power is required for the larger alternator.

[jprottas]

140amp is stock for Convertibles. Your top/electrical accessories will struggle using the 80amp. Stick with the standard equipment 140amp. 140amp is not an upgrade if you do not have a convertible. More engine power is required for the larger alternator.Thank you. Can I use the 140 bosch rebuilt regardless of which brand was in the car originally ?

Sent from my SM-N950U using Tapatalk

[darbyfam]

They have different pullies. If you are re-using the stock pulley, I think you are fine.

[pbonsalb]

Many remanufactured alternators come with the pulley. As noted, valeo and Bosch use different pulleys. I changed from an 80a valeo to a 140a Bosch and the Bosch came with pulley. Obviously try to find out first so you don’t have to it more parts than you planned.

[TostitoBandito]

Yeah, as far as I know the alternators both mount identically so they both fit and will work on any E36 M3. It's just that the pulleys vary by model.

[jprottas]

Yeah, as far as I know the alternators both mount identically so they both fit and will work on any E36 M3. It's just that the pulleys vary by model.Can you clarify: I have 99 m3 very. It takes the Bosch 140 alternator. My mechanic says it has a mechanical tensioner but all I'm finding are the hydraulic types. Would it be an upgrade to switch to a hydraulic tensioner?

Sent from my SM-N950U using Tapatalk

[jprottas]

Is Rockauto a reliable vendor for a remanufactured bosch 140 alternator or is there a safer choice for a bit more money?

Sent from my SM-N950U using Tapatalk

[Moron95M3]

Many remanufactured alternators come with the pulley. As noted, valeo and Bosch use different pulleys. I changed from an 80a valeo to a 140a Bosch and the Bosch came with pulley. Obviously try to find out first so you don’t have to it more parts than you planned.


I ended up going with the 140a as the pulley I had didn't work with the 80a I had.

...performed out of town in an autozone parking lot...so was pretty pissed when the 80A didn't work with what I had. Can't believe they had a 140a on the shelf :o