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.
READ NEXT:
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:
REMOVING AND INSTALLING/REPLACING ALL VALVES (N62) (CYLINDER HEAD
REMOVED)
Preliminary tasks are described in DISASSEMBLING AND ASSEMBLING CYLINDER
HEAD.
Remove valve springs.
Remove valve stem seals.
Remove valves from cylinder head.
Installation:
If necessary, check valve guide for wear.
If ne
NOTES ON FUEL PRESSURE CHECK (REFERENCE PRESSURE: ENVIRONMENT)
Feature of this version with ambient pressure:
The connection for the vacuum hose of the fuel pressure regulator is located
between the throttle and the air
cleaner or on the air cleaner.
Test precondition:
The correct fuel pressure reg