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
When standby state is switched on, most functions
can be used while the vehicle is stationary.
Desired settings can be adjusted.
General information
The vehicle is in the standby state after the front
doors are opened from the outside.
Display in the instrument cluster
OFF is displayed in
Concept
The Check Control system monitors functions in
the vehicle and notifies you of malfunctions in
the monitored systems.
General information
A Check Control message is displayed as a combination
of indicator or warning lights and text
messages in the instrument cluster and, if applicable,
in th