BMW 3: Belt drive

Comparison belt drive B46 engine and B46TU/B48TU engines
- B46 Engine (transverse installation shown)
- B46TU/B48TU engines (transverse installation shown)
- Deflecting element
- Alternator
- Coolant pump
- Air conditioning compressor
- Ribbed belt
- Torsional vibration damper
- Belt tensioner
The belt layout is a single-belt drive where all ancillary components are
driven by one belt.
Changing the belt guiding has help to save both material and space.
The length of the drive belt changes due to thermal expansion and ageing. So the
drive belt can
transmit the required torque, it must be continuously in contact with the belt
pulley at a defined
pressure. To allow this to happen, the belt tension is exerted by an automatic
tensioning pulley
mounted on the alternator; the pulley compensates for belt elongation over the
full service life.

In case of incorrect assembly of the drive belt, the coolant flow
through the coolant pump is either
insufficient or non-existent; there is thus a lack of cooling. There is a risk
of damage to engine
components and engine damage
READ NEXT:
Split cooling is a new development for the B46TU engine. This cooling concept
is a modified version
of which is already used in the N63TU2.
The Split Cooling function uses the electrical Split Cooli
The heat management module replaces the characteristic map thermostat.
Heat management module
Electrical Split Cooling Valve (SCV)
Coolant output towards the coolant pump
Electrical actuator
Rot
SEE MORE:
Concept
The air flow for climate control can be adjusted
manually.
General information
To adjust the air flow manually switch off AUTO
program first.
Operation
Press the lower or upper side of
the
button: decrease or increase air flow.
The selected air flow is shown on the climate
control display.
General information
Calls that are being made on the hands-free system
can be continued on the mobile phone and
vice versa.
From the mobile phone to the
hands-free system
Calls that were begun outside of the Bluetooth
range of the vehicle can be continued on the
hands-free system with standby state