BMW X5: Ignition Management
Most of the ignition system components have remained the same for all NG6 engines for 2007. There are some minor changes to the ignition coils that apply to all versions. The coils have been optimized for more durability.
Spark Plugs
The spark plugs for the N51 and N52KP remain the same as N52. However, the N54 uses a completely new spark plug from Bosch. The spark plug design consists of a 12 mm thread which contrasts from the 14 mm design on the N52 which prevents any possibility of improper installation.
The hex on the spark plug is also a 12 point design which requires a special tool. The tool (socket) has a "thinwall" design to facilitate access in the confined area of the N54 cylinder head.
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Fig. 69: Identifying Spark Plugs
Spark Plug Diagnosis (N54)
Due to the proximity of the spark plug to the fuel injector nozzle, any divergence in the fuel spray may cause possible spark plug damage. This makes spark plug diagnosis an important part of N54 service concerns.
Information gained by the spark plug diagnosis may indicate possible fuel injector faults. Spark plug replacement interval has been reduced to 45,000 miles for the N54.
The Fig. 70 below can be used to assist in diagnosis:
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Fig. 70: Identifying Spark Plug Wear Pattern
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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" c
Performance Controls
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:
Connecting Rod With Bearing
REPLACING ALL CONROD BEARINGS (N62/N62TU)
Special tools required:
00 2 590
00 9 120
11 2 110
(piston removed)
IMPORTANT: Note grinding stages on crankshaft.
The letter (1) denotes the crankshaft construction stage.
The numbers (2) denote the bearing shell classification for the relevant bearin
Turbocharger Diagnosis
There are three "Golden Rules" to adhere to when diagnosing concerns on the
N54 engine:
1. When diagnosing cases of smoke from the exhaust, it is important to avoid
unnecessary replacement of
the turbochargers. Smoke can be caused by oil consumption such as the crankcase
ventilation system.
Alwa
