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:
WARNING: Scalding hazard!
Work on independent heating may only be carried out when it has cooled
down.
Necessary preliminary tasks:
Remove left underbody panelling.
Slacken clamp (1).
Release screws (2) and remove muffler (3).
Tightening torque.
Fig. 45: Identifying Muffler/Silencer And Slack
(cylinder bank 5 to 8)
Necessary preliminary tasks:
Remove servomotor for left eccentric shaft.
Remove ignition coils on cylinder bank 5 to 8.
Remove left cylinder head cover.
Remove spark plugs on cylinder bank 5 to 8.
Remove left inlet and exhaust adjustment units.
Remove slide rail (1).