Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
12 31 020 Removing and installing or replacing alternator (N54T, N55)
2011 BMW 1MSECTION 12 31 020 Removing and installing or replacing alternator (N54T, N55)
Necessary preliminary tasks:
- Switch off ignition.
- Disconnect BATTERY NEGATIVE LEAD .
- Remove charge air duct . See 11 61 368 REMOVING AND INSTALLING/REPLACING REAR LEFT CHARGE-AIR DUCT (N54T) or 11 61 368 REMOVING AND INSTALLING/REPLACING REAR LEFT CHARGE-AIR DUCT (N55) .
- Remove alternator drive belt . See 11 28 010 REPLACING DRIVE BELT FOR ALTERNATOR (N54T) or 11 28 010 REPLACING DRIVE BELT FOR ALTERNATOR (N55) .
NOTE:
In order to remove the alternator, it is necessary to remove
the air-conditioning compressor for the air conditioning system.
In so doing:
In so doing:
- Do not draw off air conditioning refrigerant.
- Do not detach refrigerant lines from A/C compressor.
- Do not remove A/C compressor; instead, remove from bracket only and place to one side.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.