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Battery check BMW 3-Series 2005 - 2008 Petrol 330i - 3.0

OnDemand step-by-step maintenance & repair BETA

BMW 3-Series 2005 - 2008  | 330i - 3.0 Battery check

  • time 10 minutes
  • difficulty 2
Locate the battery, it's in the car's boot
Open the battery cover
Place the cover to one side
Check the Negative (-) terminal clamp is tight
Check the Positive (+) terminal clamp is tight. CAUTION – if using a spanner to tighten terminal, be careful not to short the spanner on the bodywork
Check battery is generally secure, if loose, tighten the battery retainer If you have to replace the battery or alternator, click below
- Close + Open

Battery removal & replacement

Note: When the battery is disconnected, any fault codes stored in the engine management ECM memory will be erased. If any faults are suspected, do not disconnect the battery until the fault codes have been read by a BMW dealer or specialist. If the vehicle is fitted with a code-protected audio unit, refer to the Owners handbook.

Disconnection

1 The battery is located beneath a cover on the right-hand side of the luggage compartment.
2 On Saloon models, lift the catch, and remove the left-hand side luggage compartment side trim above the battery (see illustration) . On Touring models, lift out the luggage compartment floor panel, undo the two fasteners and lift out the side panel, then rotate the two fasteners 90° anti-clockwise and lift out the trim above the battery (see illustrations) .
Rotate the catch and lift out the panel – Saloon models
Lift the handle and remove the luggage compartment floor panel
Rotate the fasteners 90° . . .
. . . and lift the base of the panel inwards to remove it
Rotate the fasteners 90° . . .
. . . and lift the panel above the battery
3 Slacken the clamp nut, and disconnect the clamp from the battery negative (earth) terminal (see illustration) . Position the negative lead away from the battery, so there is no risk of accidental contact between it and the battery terminal. For extra protection, cover the disconnected lead clamp with a rag or rubber glove, etc.
Slacken the nut and disconnect the negative lead clamp

Removal

4 Disconnect the battery negative lead as described previously.
5 Undo the 2 bolts and remove the support bracket above the battery (see illustration) .
Undo the 2 bolts and remove the bracket above the battery
6 Prise up the plastic cover, and undo the nut securing the connector assembly to the positive clamp (see illustration) .
Prise up the cover, undo the nut . . .
7 Using a flat-bladed screwdriver, lever apart the retaining clip each side and lift up the connector assembly from the top of the battery (see illustrations) . Position the connector assembly to one side.
. . . lever apart the retaining clip each side . . .
. . . and lift off the connector assembly
8 Prise up the plastic cover, slacken the nut and pull the positive clamp assembly from the terminal on the battery (see illustrations) .
Prise up the plastic cover, slacken the nut . . .
. . . and pull up the positive clamp
9 Unscrew the bolt, and remove the battery retaining clamp (see illustration) .
Undo the bolt and remove the battery retaining clamp
10 Lift the battery from its housing, disconnect the vent hose as the battery is removed (see illustrations) . Take care as the battery is heavy.
Pull the vent hose from the side of the battery . . .
. . . and lift it from place

Refitting

11 Refitting is a reversal of removal. Always reconnect the positive lead first, and the negative lead last.
12 After reconnecting the battery, several of the vehicles ECMs will require time to relearn certain values. This will normally be complete within a normal driving pattern of 15 miles (approximately). In addition, several systems may require re-initialisation as follows:
    Sunroof
    1. With the battery reconnected, and the ignition on, press the sunroof operating switch into the ‘tilt’ position and hold it there.
    2. Once the sunroof has reached the ‘fully-tilted’ position, hold the switch in that position for approximately 20 seconds. Initialisation is complete, when the sunroof briefly lifts at the rear again.
    Electric windows
    1. Operate the button to fully close the window, then continue to hold the button for at least 1 second to ‘normalise’ the anti-trapping function.
13 If a new battery has been installed, the new battery details may need be registered in the vehicles ECM using BMW diagnostic equipment (or equivalent) to enable off the convenience system/functions to operate correctly. Entrust this task to a BMW dealer or suitably equipped specialist.
- Close + Open

Alternator replacement

Removal

1 Disconnect the battery negative lead.
2 Remove the alternator drivebelt.

Petrol engines

3 Undo the 3 bolts, and pull the air intake duct rearwards/upwards and disconnect the intake hose (see illustrations) .
Undo the bolts ...
... and remove the intake duct
4 Lift the rubber cap and disconnect the airflow sensor wiring plug (see illustrations) .
Prise up the rubber cap ...
... squeeze together the sides and disconnect the air flow sensor wiring plug
5 Release the clamp and disconnect the air outlet hose from the air cleaner assembly.
6 Undo the 2 bolts securing the assembly to the inner wing, then lift it from position (see illustration) . Where necessary unclip the coolant hose as the assembly is withdrawn.
Air cleaner assembly retaining bolts
7 Unlock and disconnect the wiring plug, then unscrew the nut and disconnect the battery lead from the rear of the alternator (see illustration) .
Disconnect the wiring plug, then undo the nut securing the positive lead
8 Undo the bolts, and manoeuvre the alternator from the engine compartment (see illustration) .
Alternator mounting bolts

M57T2 diesel engines

9 Unlock and disconnect the wiring plug, then unscrew the nut and disconnect the battery lead from the rear of the alternator (see illustration) .
Depress the clip, disconnect the wiring plug, and undo the nut and disconnect the battery lead
10 Undo the bolt and remove the auxiliary drivebelt idler pulley (see illustration) .
Prise off the cap and undo the pulley retaining bolt
11 Undo the upper and lower mounting bolt, then remove the alternator (see illustration) .
Alternator mounting bolts - M57T2 diesel engines

N47 and N57 diesel engines

12 Unlock and disconnect the wiring plug, then unscrew the nut and disconnect the battery lead from the rear of the alternator (see illustration) .
Disconnect the wiring from the rear of the alternator
13 Undo the upper and lower mounting bolt, then remove the alternator (see illustration) .
Alternator mounting bolts – N47 and N57 diesel engines

Refitting

14 Refitting is a reversal of removal, tightening all fasteners to their specified torque where given.
Alternator-to-engine block: Nm Ibf ft
  Petrol engines 19 14
  Diesel engines 38 28
To tighten, a 10mm socket is needed. Not too tight as you may damage the battery casing. Replace cover
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