BMW X1 Alternator: Specs, Fitment & Common Faults
On the X1, a leaking oil filter housing gasket has genuinely been documented as a primary cause of alternator failure on related engines.
Illustration for editorial purposes
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OEM Part Number: 12317558219 (genuine alternator — confirm via VIN) — aftermarket alternators Denso DAN1464 / Hella 8EL 015 630-481
| Alternators (aftermarket) | Hella 8EL 015 630-481 (180 A, V-ribbed pulley, 6 ribs, 48 mm, new); Denso DAN1464 (180 A, multi-rib pulley, 6 ribs, 48 mm, new); Lucas LRA04380 (120 A, multi-rib pulley, 6 ribs, 49 mm, remanufactured, plug 0336, core charge £40.19); AS-PL A6415S (180 A, 6 ribs, 49 mm, new, plug PL_2306); AS-PL A6926S (180 A, 6 ribs, 49 mm, new, plug PL_2818); AS-PL A6856S (150 A, 6 ribs, 49 mm, new, plug PL_2801); AS-PL A6890S (120 A, 6 ribs, 49 mm, new, plug PL_2801); Ridex 4G1138 (180 A, multi-rib pulley, 6 ribs, 48 mm, new, excludes vacuum pump) |
|---|---|
| Outputs & variants | Four outputs are listed on a 48-49 mm six-rib pulley: 120 A for the 1.5 three-cylinder sDrive18i, 150 A for the sDrive16d and 18d, 180 A for the 20i, 20d and 25d, and a 210 A BV PSH 215.913.210.346 for the highest-load cars. No reference specifies a freewheel pulley; all are rigid multi-rib pulleys. |
| Genuine (OE) numbers quoted | 104210-6721 (AS-PL A6415S), 104211-0740 (AS-PL A6926S), 104211-3990 (AS-PL A6890S), 104211-9200 (AS-PL A6856S and Rotovis 9091002). |
| Fitment notes | These are Denso-built units and the different outputs look alike, so the Denso or BMW number on the old alternator should be checked before ordering; the Ridex unit is supplied without the vacuum pump, and the remanufactured Lucas and Walker units carry a core charge refunded on return of the old alternator. |
BMW X1 Alternator: Often Blamed on the Battery Instead
On the BMW X1, dim lights, slow starts, a battery that won't hold charge — these symptoms point equally to a weak battery or a failing alternator, and that overlap is why so many replacements target the wrong part first, with the real problem only surfacing weeks later.
BMW X1 Alternator: What It Does
Electricity generation while the BMW X1's engine is running is the alternator's job, charging the battery and directly powering the electrical systems. When it's working properly, the battery mostly just handles engine starting and short demand spikes, not day-to-day electrical load.
BMW X1 Alternator: Watch: Replacing It
E84 X1 with N20; F48 only has thermostat/water-pump and diode-test videos.
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A Genuinely Important, BMW-Specific Finding Worth Knowing — BMW X1 Alternator
If this alternator has failed, this is genuinely worth checking before fitting a replacement: a leaking oil filter housing gasket has been documented as a primary cause of alternator failure on related BMW engines, since leaking oil can drip directly onto the alternator and cook its internal components.
It's also genuinely worth knowing that when replacing the alternator, it's wise to also change the serpentine belt, tensioner, and idler pulley at the same time, particularly if they're oil-soaked or high-mileage.
BMW X1 Alternator: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Alternator Guide for symptoms to watch for (plus a genuinely useful two-minute test to confirm it's not the battery instead), confirming the right amperage and fitment against your VIN, and which brands are worth trusting.
More BMW Alternator
The same part, covered across other BMW models.