BMW 328i Alternator for Sale | OEM 12V 120A to 180A for E90 and F30 328i
$150.00
At a Glance
- Condition: OEM used, output amperage tested before shipping
- Availability: In stock for E90 and F30 328i
- Shipping: Free shipping to all 50 states, 5 to 10 business days
- Output amperage tested (120A to 180A verified)
- Voltage regulator function verified (13.8V to 14.5V output)
- Bearing and pulley condition inspected
- Brush condition inspected
- Engine type confirmed (N52, N51, or N20) before shipping
- Compatible with E90 (2007 to 2013) and F30 (2012 to 2018)
- 100% fitment verified before every order ships
- Backed by a 15 day replacement warranty against operational defects
Description
About the BMW 328i Alternator
The BMW 328i alternator is a vital component of the vehicle electrical and charging system. It converts mechanical energy from the engine (transferred through the serpentine belt) into electrical energy to power all vehicle electrical components (lights, infotainment, fuel pump, ignition, climate control, ECU) and to recharge the battery while the engine is running. The 328i nameplate spans two distinct chassis generations: the E90 (2007 to 2013) with the N52 inline-six naturally aspirated engine, and the F30 (2012 to 2018) with the N20 turbocharged inline-four engine. Output amperage varies by application, ranging from 120A on early E90 builds to 180A on later F30 N20 builds with their increased electrical demand.
Why BMW 328i Owners Replace the Alternator
Common 328i alternator replacement triggers include:
- Battery warning light on dashboard: Charging system not maintaining proper voltage
- Dimming or flickering headlights: Voltage drop under load
- Battery drain or repeated dead battery: Alternator not maintaining battery charge
- Vehicle stalls and will not restart: Severe charging failure
- Voltage reading below 13.8V at idle: Faulty voltage regulator
- Voltage reading above 15V: Failed voltage regulator (overcharging damages battery and electronics)
- Whining or grinding noise from alternator area: Failed bearings
- Burning smell from engine bay: Burned-out diode pack or rectifier
- Brush wear after high mileage: Typical 80,000 to 150,000 mile interval
Common BMW 328i Alternator Failure Modes
| Detail | Description |
|---|---|
| Brush Wear | Carbon brushes wear out after 80,000 to 150,000 miles, causing intermittent charging |
| Voltage Regulator Failure | Solid-state regulator fails, causing overcharging or undercharging |
| Diode Pack Failure | Internal diodes (rectifier) fail, causing AC ripple in DC output |
| Bearing Wear | Front or rear bearing fails, causing whining noise and eventual seizure |
| Pulley Failure | Overrunning alternator pulley (OAP) fails on N52 engines specifically |
| Coolant Intrusion (rare) | Coolant leak from nearby hose damaging windings (most common on older E90s) |
Things to Confirm Before Ordering
- Chassis (E90 2007 to 2013 vs F30 2012 to 2018)
- Engine code (N52 inline-six naturally aspirated, N51 SULEV variant, or N20 turbocharged inline-four)
- Year (2012 has overlap of E90 and F30, confirm by VIN if uncertain)
- Output amperage required for your application (typically 120A to 180A)
- xDrive vs RWD (different bracket on some applications)
What Ships and What Does Not
| Item | Details |
|---|---|
| INCLUDED | Used OEM alternator with pulley, voltage regulator, brushes, bearings, and integrated cooling fans. |
| NOT INCLUDED | Serpentine belt (replace if worn), battery (sold separately), wiring harness, mounting bracket (typically reuses your vehicle’s existing bracket). |
| Tools You Need | Standard hand tools, 13 mm and 16 mm sockets typical, serpentine belt tensioner tool, possibly engine cover removal tool, basic electrical multimeter for output verification post-install. |
Vehicle Compatibility
This BMW 328i alternator is compatible with the following:
| Vehicle | Compatibility |
|---|---|
| BMW 328i E90 Sedan (2007 to 2013) | N52 3.0L naturally aspirated I6 engine, RWD and xDrive |
| BMW 328i E91 Touring/Wagon (2007 to 2013) | Same engine as E90 sedan |
| BMW 328i E92 Coupe (2007 to 2013) | Same engine as E90 sedan |
| BMW 328i E93 Convertible (2007 to 2013) | Same engine as E90 sedan |
| BMW 328i F30 Sedan (2012 to 2018) | N20 2.0L turbocharged I4 engine, RWD and xDrive |
| BMW 328i F31 Touring/Wagon (2013 to 2019) | N20 engine |
| BMW 328i F34 Gran Turismo (2013 to 2019) | N20 engine |
| BMW 328d (E90, F30 diesel variants) | Some applications share alternator spec, confirm by engine code |
NOT compatible with: 320i (lower-output alternator on some years), 335i with N54 or N55 engine (different alternator with higher output), 340i with B58 engine (different spec), G20 3-Series (2019 onward, redesigned chassis).
Inspection Workflow
Every used BMW 328i alternator we ship goes through this process:
- Output amperage tested (verified 120A to 180A under load matching application spec)
- Voltage regulator function verified (output between 13.8V and 14.5V at idle)
- Bearing condition inspected (no roughness, no whining)
- Pulley integrity verified (overrunning function tested on N52 OAP applications)
- Brush condition inspected (sufficient brush material remaining)
- Diode pack tested (no AC ripple in DC output)
- Connector pin integrity verified
- Donor application and engine code documented
These are used OEM alternators, not new. Cosmetic wear is normal on used alternators and disclosed before shipping.
Why Buy From Part Nests
- Tested OEM BMW 328i alternator with output amperage verified
- Voltage regulator function tested (13.8V to 14.5V output)
- Engine code confirmed (N52, N51, or N20) before shipping
- Bearing and pulley condition inspected
- Brush condition verified
- Compatible with E90 (2007 to 2013) and F30 (2012 to 2018)
- Free shipping to all 50 states, no hidden surcharges
- 15 day replacement warranty on operational defects
- Call (855) 634-4447 to match VIN to the correct alternator variant for your N52, N51, or N20 application
15 Day Replacement Warranty
Every used BMW 328i alternator purchased through Part Nests carries a 15 day replacement warranty starting on the delivery date.
What Is Covered
- Operational defects: output amperage failures, voltage regulator failures, or bearing failures beyond what was disclosed
- Diode pack failures (AC ripple in DC output) not disclosed at shipping
- Brush failures within 15 days from installation
- Incorrect engine variant shipped (N52 vs N51 vs N20) due to an error on our end
What Is Not Covered
- Damage caused during installation
- Damage from installing with reversed polarity or incorrect serpentine belt routing
- Damage from operating with a known short or overload on the charging circuit
- Damage from a failed serpentine belt or tensioner
- Labor expenses of any kind
To start a warranty claim, reach us within 15 days of delivery at (855) 634-4447.
- Output Amperage Tested: 120A to 180A verified under load
- Voltage Regulator Function Verified: 13.8V to 14.5V at idle
- Bearing Condition Inspected: No roughness, no whining
- Brush Condition Inspected: Sufficient material remaining
- Engine Code Confirmed: N52, N51, or N20 documented before shipping
- 15 Day Replacement Cover: Operational defects protected from delivery onward
Additional information
| application | BMW 328i (E90 2007 to 2013, F30 2012 to 2018) |
|---|---|
| compatible-engines | N52, N51, N20 |
| voltage | 12V DC |
| output-amperage | 120A to 180A (varies by application) |
| voltage-regulator | Internal solid-state |
| pulley-type | Serpentine multi-groove (6-rib N52, 7-rib N20) |
| rotation-direction | Clockwise viewed from pulley end |
Three different engines under the 328i nameplate. The N52 is the 3.0L naturally aspirated inline-six used in E90 328i applications (2007 to 2013). The N51 is a SULEV (Super Ultra Low Emission Vehicle) variant of the N52 with revised emissions equipment, used in specific California-emissions 328i applications. The N20 is the 2.0L turbocharged inline-four used in F30 328i applications (2012 to 2018). The three engines use different alternator variants with different output ratings and bracket mounting. Always confirm engine code before ordering.
Production year is the easiest indicator. 2007 to 2011 = E90 exclusively. 2012 = transition year, can be either E90 or F30 depending on production date. 2013 to 2018 = F30 exclusively. The chassis is also identified in the VIN; we can look this up at order. Visually, the E90 has slightly narrower headlights and the older BMW twin-kidney grille; the F30 has the larger modernized grille and longer wheelbase that became the BMW signature in the 2010s.
Common signs: dashboard battery warning light, dimming or flickering headlights especially under load, repeated dead battery despite a known-good battery, vehicle stalls and will not restart, whining or grinding noise from the alternator area, or burning smell from the engine bay. Voltage testing at the battery (should read 13.8 to 14.5V at idle with the engine running) confirms whether the alternator is the problem; below 13.8V indicates a charging system fault, above 15V indicates an overcharging regulator failure.
A pulley with a built-in one-way clutch. Used on the N52 engine to absorb crankshaft torsional vibrations and reduce alternator bearing wear. The OAP allows the alternator to overrun the belt during deceleration. OAP failure causes whining, vibration, and reduced charging output. The N20 typically uses a standard solid pulley. We test OAP function on every N52 alternator before shipping.
No. The E90 N52 alternator and F30 N20 alternator are different units with different mounting brackets, output ratings, and pulley configurations. They are NOT interchangeable across chassis generations even though both vehicles wear the 328i badge. Always confirm chassis and engine code when ordering.
Application-specific. Early E90 builds with fewer electrical accessories typically used 120A to 150A alternators. Later F30 builds with more electronics, larger infotainment, and start-stop systems used 170A to 180A alternators. Downgrading to a lower-output alternator can cause undercharging on a heavily-equipped vehicle. We match output amperage to your specific application before shipping.
Strongly recommended on high-mileage vehicles. The serpentine belt ages along with the alternator and often needs replacement at the same labor visit. A failed belt damages the new alternator pulley and other accessory drive components. Belt cost is small relative to the alternator; replacing both at the same labor visit makes economic sense. Inspect the tensioner and idler pulleys at the same time.
No. There is no core return required.
2 reviews for BMW 328i Alternator for Sale | OEM 12V 120A to 180A for E90 and F30 328i
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Liam P. –
Got a 328i alternator for a 2010 E90 N52. Engine code confirmed up front (N52 inline-6, not the SULEV N51 variant), output amperage tested at 150A under load, OAP pulley function verified. Drop-in replacement after the original had been intermittently undercharging. Voltage at battery now reads 14.2V at idle.
Naomi B. –
Sourced a 328i alternator for a 2015 F30 N20 turbo. Engine variant correctly identified (N20 2.0T, not N52), output rated at 180A for the higher electrical demand of the turbo car. Bearings and brushes inspected, voltage regulator tested. Honest pre-purchase information about the E90 vs F30 alternator non-interchangeability.