Obviously the engines are supposed to sound different...
1998 (1998 for euro versions)-2000 323i's and 328i's use a m52 tu engine
For 2000 models on up 325's and 330's used the M54 Engine
Purpose of the System
The M54 engine was development to meet the needs for ULEV compliancy for emission control. The increase in displacement allows the engine to kit the X5 All Roads vehicles while still meeting the demands for power and performance.
The M54 - 6 cylinder engine is being introduced with the 2001 model year E53 - X5. The displacement of the new engine for the X5 is 3 liters and the engine will replace the 2.8 liter engine in the E46/E36-Z3 series in the 6/2000 and E39 series vehicles in 9/2000 production in the E46/E36 Z3 and E39 vehicles.
Although the E53 X5 with the M54 engine will be LEV compliant, the M54 - 3 liter displacement engine meets ULEV compliancy, for emission standards, for the balance of the product. The 2.5 liter version of the M54 engine will remain LEV compliant.
Design objective for the M54 engine were to provide
* Lower emissions
* Maintain Fuel Economy
* Maintain Power and Performance levels.
Specs on the M54-B30
231 bhp @ 5900rpms
300Nm @ 3500rpms (221ft.lbs)
Specs on the M54-B25
192 bhp @ 6000rpms
245Nm @ 3500rpms (180ft.lbs)
M54 Engine - Mechanical Changes
NEW PISTONS - The piston has a shorter skirt compared to the M52TU and continues with the graphite coating for friction and emission reducing measures. The piston rings have been modified to reduce friction.
CRANKSHAFT - The crankshaft for the 3 liter M54 is adopted from the S52-B32 - M3 engine. The crankshaft for the 2.5 liter is carried over from the M52.
CAMSHAFT - The camshaft for the 3 liter M54 is modified with more lift and new valve springs to accommodate the increased lift. The camshaft of the 2.5 liter M54 is carried over from the M52 engine.
INTAKE MANIFOLD - The intake manifold is modified with the shorter ram tubes (20mm shorter on 3 liter/10mm shorter on the 2/5 liter). The diameter of the tubes is increased slightly.
INJECTION VALVES - The diameter of the injection pintle has increased slightly for the increased displacement of the 3 liter engine. The injector for the 2.5 liter engine carries over from M52.
NON RETURN FUEL RAIL SYSTEM - The M54 engine MS 43.0 control uses the non return fuel rail system introduced on the M62TU engine. The system meets running loss compliance without the use of the 3/2 way solenoid valve currently used on the M52TU engine.
The regulated fuel supply is controlled by the fuel presure regulated integrated in the fuel filter. The fuel return line is also located on the filter.
The M54 engine uses an Electronic Controlled Throttle Valve (EDK) for intake air control. The idle control valve and turbulence function of the intake manifold carries over from the M52TU engine.