Engine Codes Covered:
N42B20, M54B22, M54B25, M54B30, M47TUD20
Body Styles Covered:
Sedan (E46/4), Coupe (E46/2), Convertible (E46/C), Touring (E46/3), Hatchback (E46/5 - 3 Series Compact)
Positioning:
The BMW E46 (1998-2006) was a highly successful premium compact executive car, praised for its driving dynamics, build quality, and sophisticated engineering. The 2003 model year represents a significant point in its lifecycle, often featuring mid-cycle updates.
Competitors:
Competed directly with the Mercedes-Benz C-Class (W203), Audi A4 (B6), Lexus IS, and Infiniti G35. The E46 was often lauded for its superior handling and driver engagement compared to many rivals.
Design:
Iconic BMW design language, excellent weight distribution, driver-focused interior.
Performance:
Renowned for its balanced handling, responsive engines, and engaging driving experience, especially in M Sport variants.
Reliability:
Generally considered reliable with proper maintenance, though specific E46 common issues are well-documented.
Primary Coverage:
Comprehensive repair and service procedures for the 2003 BMW E46 generation.
Specific Areas:
Engine, Drivetrain, Suspension, Steering, Brakes, Electrical System, Climate Control, Bodywork, Diagnostics.
Type:
Factory Service Manual (FSM) / Repair Manual
Powertrain:
Engine mechanicals, fuel injection, ignition, exhaust, cooling, lubrication, engine management (DME), automatic and manual transmissions, clutch, driveshafts, differentials, axles.
Chassis:
Front and rear suspension (McPherson struts, multi-link), steering system (rack and pinion, power steering), brake system (ABS, DSC, rotor/pad replacement, caliper service), wheel bearings, subframes.
Electrical:
12V battery system, alternator, starter, lighting (headlights, taillights, interior), power windows/locks, central locking, instrument cluster, warning indicators, fuse and relay locations, basic wiring diagrams.
Body Interior:
Body panel removal/installation, door mechanisms, interior trim, seats, dashboard, bumpers, trunk lid, hood.
Climate Control:
HVAC system operation, refrigerant handling, blower motor, heater core, A/C compressor, control modules.
Maintenance:
Oil and filter changes, coolant flushes, spark plug replacement, air filter replacement, brake fluid service, fuel filter replacement, drive belt inspection/replacement, battery testing.
Diagnostics:
Troubleshooting guides, fault code interpretation (OBD-II), common symptoms and causes, diagnostic procedures for various systems.
Repair Rebuild:
Engine disassembly and reassembly, transmission overhaul, brake caliper rebuilding, suspension component replacement, steering rack replacement, alternator/starter replacement, fuel pump replacement.
Installation Adjustment:
Accessory installation, sensor replacement, component calibration, headlight alignment, suspension alignment specifications.
Depth:
Highly detailed, covering everything from basic fluid checks and filter replacements to complete engine and transmission rebuilds. Includes torque specifications, clearances, and diagnostic flowcharts.
2.5L Inline-6 (M54B25):
Displacement: 2494 cc (2.5L), Bore x Stroke: 84 mm x 75 mm, Compression Ratio: 10.2:1, Horsepower: 189 hp @ 6000 rpm, Torque: 181 lb-ft @ 3500 rpm, Engine Code: M54B25
3.0L Inline-6 (M54B30):
Displacement: 2979 cc (3.0L), Bore x Stroke: 84 mm x 89.6 mm, Compression Ratio: 10.2:1, Horsepower: 225 hp @ 5900 rpm, Torque: 214 lb-ft @ 3500 rpm, Engine Code: M54B30
2.0L Inline-4 (N42B20):
Displacement: 1995 cc (2.0L), Bore x Stroke: 82 mm x 94.6 mm, Compression Ratio: 10.0:1, Horsepower: 143 hp @ 6200 rpm, Torque: 147 lb-ft @ 3750 rpm, Engine Code: N42B20
2.0L Diesel (M47Tud20):
Displacement: 1995 cc (2.0L), Bore x Stroke: 84 mm x 90 mm, Compression Ratio: 18.0:1, Horsepower: 150 hp @ 4000 rpm, Torque: 236 lb-ft @ 1750 rpm, Engine Code: M47TUD20
Redline:
Typically 6500 rpm for M54 engines, 6200 rpm for N42.
Engine Management:
Bosch Motronic (e.g., ME7.x for gasoline, EDC16 for diesel).
Fuel Delivery:
Electronic Fuel Injection (EFI), often with a Bosch Motronic control unit.
Fuel Type:
Premium Unleaded Gasoline (91 AKI or higher recommended for M54), Diesel for M47.
Engine Oil:
BMW Longlife-01 (LL-01) certified synthetic oil, e.g., 5W-30 or 0W-30. Check specific model requirements.
Coolant:
BMW Blue Antifreeze/Coolant (G48 ethylene glycol based) mixed 50/50 with distilled water.
Transmission Type:
5-speed Manual Getrag GS53Z (for most gasoline models) or ZF 5HP19 automatic (for most gasoline models).
Transmission Type:
6-speed Manual Getrag SG170 (for select high-performance models like 330i ZHP), Steptronic automatic (5-speed ZF 5HP19TU).
Clutch:
Hydraulically operated single dry plate clutch for manual transmissions.
Automatic Features:
Sport and Steptronic modes allowing manual gear selection via shifter or steering wheel buttons (on some models).
Manual Transmission Fluid:
BMW MTF LT-2 or equivalent (e.g., Pentosin MTF2). Check specific manual for viscosity.
Automatic Transmission Fluid:
BMW ATF LT-71141 (for ZF 5HP19) or BMW ATF 6 (for newer ZF transmissions if applicable). Check specific manual.
IIHS Front Crash:
Good (for models tested)
NHTSA Side Impact:
Good (for models tested)
Traction Control:
Available, often as ASC+T (Automatic Stability Control + Traction) or DSC (Dynamic Stability Control).
ABS:
Standard Anti-lock Braking System.
Stability Control:
Dynamic Stability Control (DSC) available, often standard on higher trims or as an option.
Airbags:
Frontal airbags (driver and passenger), optional side airbags, optional head protection system (HPS).
Seatbelts:
3-point inertia-reel seatbelts with pretensioners and force limiters, rear seat belts.
Head Unit:
BMW Business CD, BMW Professional CD RDS, optional navigation systems (Mk3/Mk4).
Display:
Central LCD screen for climate control, radio, and navigation information. Optional widescreen for navigation.
Parking Assist:
Optional rear parking sensors (Park Distance Control - PDC).
Cruise Control:
Standard on most models.
Audio Inputs:
Typically CD player, AM/FM radio. Optional CD changer. Aftermarket AUX inputs are common modifications.
Bluetooth:
Optional Bluetooth phone preparation available on some models with integrated phone cradle and hands-free functionality.
Oil Change Interval:
Typically every 10,000-15,000 miles (16,000-24,000 km) or annually, as indicated by the Condition Based Service (CBS) system or oil quality sensor.
Inspect Brakes Interval:
Every 12 months or 10,000 miles, or as indicated by CBS. Pad wear sensors will trigger a warning.
Coolant Flush Interval:
Every 2-3 years or as indicated by CBS.
Spark Plug Replacement Interval:
M54 engines: ~100,000 miles (160,000 km) for iridium plugs. N42 engines: ~60,000 miles (100,000 km) for platinum plugs. Always check manual for specifics.
Air Filter Replacement Interval:
Every 30,000 miles (48,000 km) or as needed based on conditions.
Power Steering Fluid:
BMW Power Steering Fluid (ZHM) or Pentosin CHF 11S. Incorrect fluid can damage the system.
Brake Fluid:
DOT 4 Low Viscosity (LV) brake fluid. Flush every 2 years.
Cooling System:
Plastic expansion tank cracks, water pump failure (especially plastic impeller versions), coolant hose leaks, thermostat housing leaks.
Suspension:
Front control arm bushings (vibrations), rear trailing arm bushings, ball joints, strut mounts, sway bar links.
Engine M54:
PCV system issues (vacuum leaks, oil consumption), VANOS solenoids/seals, oil filter housing gasket leaks, crankshaft position sensor failures.
Electrical:
ABS/DSC module failure, instrument cluster pixel degradation, door lock actuator failures, LCM (Light Control Module) issues.
Body Interior:
Headliner sagging, door seal deterioration, trunk drain issues leading to water ingress.
Bmw Legacy:
BMW, known as Bayerische Motoren Werke AG, has a long history dating back to 1916, establishing itself as a premium manufacturer of sporty and luxurious vehicles.
E46 Introduction:
The E46 generation replaced the E36 3 Series and was produced from 1998 to 2006, with the 2003 model year being part of the facelifted (LCI) phase, which introduced revised styling and updated features.
Facelift 2003:
The 2003 model year (often referred to as LCI - Life Cycle Impulse) brought subtle exterior design changes (e.g., revised headlights, taillights, bumpers) and interior upgrades, including updated iDrive systems on certain models.
Production Period:
1998-2006 (E46 generation)
Manufacturing Locations:
Germany ( utama), Austria, South Africa, China, Thailand, and others.
Car And Driver:
Car and Driver 10Best list multiple times during its production run, highlighting its superior handling and performance.
Ward:
Recognized for its acclaimed inline-six engines by Ward's AutoWorld.
Consumer Reports:
Generally rated well for owner satisfaction, though with specific points of concern regarding reliability in certain areas, particularly as the vehicles age.
Safety Certifications:
Meets all relevant US Federal Motor Vehicle Safety Standards (FMVSS) for its model year.
