Description - MG MG6 Series 2011 Service Manual

Engine

Description

General
The starting system on the vehicle comprises a 12V starter
motor. The starter motor converts electrical energy into
mechanical energy.
Starter Motor
The starter motor is located at the LH rear of the engine
and is secured to threaded holes in the gearbox casing with
two flanged bolts. A 1.2kW starter motor is fitted to vehicles
with manual transmission. The mechanical energy of the pinion
turns the flywheel; the low gear ratio between the two allows
sufficient torque to start the engine.
Each starter motor is of pre-engaged type and comprises of
a series wound motor, an overrunning clutch and an integral
solenoid. Both are of conventional layout with the motor
in-line with the pinion and the solenoid mounted above. A
single connector on the starter motor provides the connection
to the immobilisation module. A 25 mm cable connects the
battery positive terminal directly to the starter motor via a
copper threaded stud and is secured with a nut.
Alternator
All models are fitted with a 120 Amp alternator located at
the RH front of the engine secured to two aluminium brackets
with two bolts and flanged nuts. A drive pulley is attached
to one end of the rotor and is driven by a polyvee belt from
the crankshaft. Belt tension is maintained by a friction damped
tensioner. The instrument pack incorporates a charge warning
light which illuminates when there is no output or a low output
from the alternator.
The alternator comprises of a stator, a rotor, a rectifier pack
and a regulator. The alternator provides the connections for
the charge warning light, ignition supply andECMcharge signal.
The alternator is connected to the battery using a 12 mm cable,
via a fuse link, and is connected to earth via its mountings.
The stator comprises of a stator core and a stator coil
which are supported by frames at each end. The stator is
manufactured from laminated soft iron plates with slots to
accommodate the stator coil and is secured to the alternator
casing. The stator has three sets of coils made from heavy
gauge, enamelled copper wire.
The three coil windings are connected in a 'star connection',
where one end of each winding is connected to the other two.
The output current is supplied from the opposite end of each
winding. The stator core allows the magnetic flux produced
by the rotor poles to flow across the stator coil.
The rotor comprises of a field winding, wound around an iron
core and mounted on a shaft. The iron core has extensions
at each end which form North and South poles as current
flows through the field winding. The rotor is located inside
Version 2.0
the stator and is mounted on bearings for smooth running and
to support the rotor due to the high side loading applied by
the drive belt tension. The rectifier, located at the rear of the
alternator comprises eight semi-conductor diodes mounted on
a heat sink to dissipate heat. Three diodes are on the positive
side and three on the negative side with the two remaining
diodes being neutral.
The integrated circuit regulator is also located at the rear of
the alternator.
Battery
Warning: Battery fluid (electrolyte) contains sulphuric
acid. It may cause severe burns if it gets on your skin or
in your eyes. Wear protective clothing and a face shield.
If electrolyte gets on your skin or clothes, immediately
rinse it off with water. If electrolyte gets in your eyes,
immediately flush eyes with water for at least 15 minutes
and seek medical help.
Caution: When removing the battery, ensure that the
alarm is disarmed and that the ignition is switched off.
Always disconnect the negative terminal first and then
the positive terminal. When refitting the battery, always
fit the positive terminal first followed by the negative
terminal.
Caution: If the battery is removed for repair, make sure
that the battery fitting belt does not cover the ventilation
hole on top of the battery.
Caution: If the battery is discharged it must be removed
from the vehicle for recharging.
charger must be used to recharge the battery. A fast
charger MUST not be used or permanent damage to the
battery may occur.
All vehicles are fitted with a 12V, 60A/h, maintenance free,
lead/sulphuric-acid battery located on the LH side of the engine
compartment, housed on a pressed steel carrier fixed to the
gearbox mount, secured with a fabric strap and enclosed in a
heat shield. The battery terminals are of the post type using
clamp type connections.
The battery has both positive and negative plates with grids
expanded from a strip leadcalcium alloy.
provides improved durability of the mechanical integrity of the
plate packs and reduces electrolyte loss when compared to
previous technologies.
The battery is completely sealed, but the vent hole on the head
cover allows releasing oxygen and hydrogen generated which
will make the battery become over-charged.
The battery uses a complete hydrometer with temperature
compensation to provide direct instruction about electrolyte's
density and fluid level. Different colors displayed on the
Engine Electrical System
A constant current
This technology
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