BMW X5: Emissions Management
The N54 and N52KP meet ULEV II requirements for 2007. There are not many
changes to the emission
systems on these engines. The N54 engine has 2 underbody catalysts in addition
to the "near engine" catalysts
already in use from the N52.
The N51 engine, however, is a SULEV II compliant engine which meets the 2007
requirements. In addition to
the 5 existing SULEV states of California, New York, Maine, Massachusetts, and
Vermont - four states have
been added for 2007. These states include, Connecticut, Rhode Island, Oregon and
Washington State.
The N51 emissions measures include:
- Secondary Air System with mini-HFM
- Radiator with "Prem-air" coating
- Lower compression ratio (10:1) via modified combustion chamber and
pistons
- Underbody catalyst in addition to "near engine" catalyst
- Activated carbon air filter in air filter housing
- Steel fuel lines with threaded fittings and sealed fuel tank
- Crankcase ventilation system integrated into cylinder head cover
- Purge system piping made from optimized plastic
NOTE: The SULEV II information above is only preliminary and is
accurate as of 8/06.
Additional information will be released as it becomes available.
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Cooling System
The cooling system of the N54 engine consists of a radiator circuit and an
isolated oil cooling circuit. The fact
that there is an isolated oil-cooling circuit ensures that heat is not
SEE MORE:
The following system functions are described:
Power management
Electronic immobilizer
Comfort start
Air supply: 2-stage differentiated air intake system "DISA"
Charge monitoring
"Valvetronic" variable valve gear
"VANOS" variable camshaft control
Fuel supply system
Fuel injection
Ignition-
IMPORTANT: The brake pad wear sensor must be replaced once it has been
removed (brake
pad wear sensor loses its retention capability in the brake pad).
If a brake lining sensor that has already been ground has to be replaced even
though the minimum brake pad thickness has
not yet been reached, you