Coolant pump
A centrifugal-type coolant pump is
mounted to the front of the engine. The
belt-driven pump circulates coolant
through the system whenever the engine
is running.
Thermostat
An electrically heated thermostat
regulates the engine coolant
temperature and is controlled by the
DME control module. The heated
thermostat allows the engine to be
operated at higher temperatures at idle
and at part throttle. Having the ability to
control the engine coolant temperature
electronically results in improved
emissions and performance. Problems
with the heated thermostat can be
diagnosed using a compatible scan tool.
Radiator and expansion tank
The radiator is a crossflow design. An
expansion tank provides for coolant
expansion at higher temperatures and
easy monitoring of the coolant level.
On cars with automatic transmission,
ATF is circulated through an additional
heat exchanger (ATF cooler).
Cooling fan (primary)
The are two cooling fan configurations
used on the cars covered by this
manual, depending on transmission
Radiator and Cooling System
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Summary of Contents for 1999-2005 M3
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