Positioning:
The BMW M3 Convertible (E46) represented the pinnacle of performance motoring in the compact executive convertible segment during its production run. Known for its exhilarating driving dynamics and powerful inline-six engine, it was a direct competitor to vehicles like the Mercedes-Benz CLK AMG and Audi RS4 Cabriolet.
Competitors:
Mercedes-Benz CLK AMG (W208/W209), Audi S4/RS4 Cabriolet (B6/B7), Porsche 911 Carrera Cabriolet.
Driving Dynamics:
Renowned for its balanced chassis, precise steering, and high-revving S54 engine, offering a pure driving experience.
Convertible Top:
Sophisticated electro-hydraulic convertible top mechanism, providing open-air motoring.
Engine:
S54 3.2L Inline-6, DOHC, VANOS, individual throttle bodies, cooling system, lubrication system, fuel system, ignition system, emissions control
Transmission:
SMG (Sequential Manual Gearbox) & 6-Speed Manual, clutch, gearbox operation, diagnostics, fluid service
Drivetrain:
Rear-wheel drive, driveshaft, differential, axle shafts, limited-slip differential (if equipped)
Suspension:
Front McPherson strut, rear multi-link, springs, dampers, bushings, steering system (hydraulic power steering), wheel alignment
Brakes:
Front and rear disc brakes, ABS, DSC (Dynamic Stability Control), brake fluid specifications, caliper service, rotor replacement
Electrical:
Battery, alternator, starter, lighting system, fuse box locations, wiring diagrams, DME (Digital Motor Electronics), instrument cluster, comfort electronics
Bodywork:
Convertible top mechanism (hydraulic and electrical), body panel removal and installation, interior trim, door mechanisms, seals
Climate Control:
HVAC system operation, refrigerant, compressor, blower motor, cabin filter replacement
Maintenance:
Oil changes, filter replacements (oil, air, cabin), spark plug replacement, brake fluid flush, coolant flush, differential fluid change, transmission fluid change, inspections
Troubleshooting:
Diagnostic trouble codes (DTCs), common symptoms, fault isolation procedures for engine, transmission, electrical, and mechanical systems
Repair:
Engine component replacement (e.g., VANOS solenoids, throttle bodies), clutch replacement, brake component overhaul, suspension bushing replacement, convertible top repair, electrical component diagnosis and replacement
Diagnostics:
On-board diagnostics (OBD-II), DME fault codes, system checks, sensor testing, actuator testing
Depth:
Comprehensive diagnostic and repair procedures, including detailed component removal and installation steps, torque specifications, special tool requirements, and system schematics.
Engine Type:
Naturally Aspirated Inline-6
Displacement:
3.2 Liters (3246 cc)
Bore X Stroke:
87.0 mm x 91.0 mm
Compression Ratio:
11.5:1
Valvetrain:
DOHC, 24 valves, Double VANOS (variable valve timing)
Horsepower Us Spec:
333 hp @ 7900 rpm
Torque Us Spec:
262 lb-ft @ 4900 rpm
Fuel Delivery:
Electronic Fuel Injection (EFI) with individual throttle bodies (ITBs)
Fuel Type Recommended:
Premium Unleaded Gasoline (91+ Octane)
Coolant Type:
BMW Blue Antifreeze (G48 formulation) or equivalent
Oil Type Recommended:
SAE 10W-60 Synthetic Engine Oil (e.g., Castrol TWS Motorsport or BMW High Performance Syn)
Oil Capacity With Filter:
7.5 Liters (7.9 US Quarts)
Type:
6-Speed Manual (Getrag 420G)
Type:
6-Speed Sequential Manual Gearbox (SMG II)
Clutch:
Hydraulic twin-plate clutch for manual, electronically controlled clutch for SMG
Manual Transmission Fluid:
BMW MTF LT-2 (or Pentosin MTF 2)
Smg Hydraulic Fluid:
Pentosin CHF 11S (for SMG hydraulic system)
Type:
Limited-Slip Differential (M Variable Lock)
Fluid Type:
BMW Hypoid Gear Oil G2 (or equivalent GL-5 specification, e.g., Red Line 75W-90 NS)
NHTSA Front Impact:
4-star (as part of E46 3 Series convertible)
NHTSA Side Impact:
5-star (as part of E46 3 Series convertible)
Stability Control:
Dynamic Stability Control (DSC), including ABS and traction control
Braking System:
M Sport Brakes (larger rotors and calipers), DSC with specific M tuning
Headlight System:
Bi-Xenon Adaptive Headlights (optional)
Airbags:
Front dual-stage airbags, front side-impact airbags, rollover protection system (automatic pop-up roll bars)
Body Structure:
Reinforced A-pillars and side sills for convertible rigidity and crash protection.
Head Unit:
BMW Business or Professional CD radio, often with optional navigation system (MKIV system).
Audio System:
Optional Harman Kardon sound system.
Traction Control:
Dynamic Traction Control (DTC) and Dynamic Stability Control (DSC)
Parking Assist:
Optional rear park distance control (PDC).
Bluetooth:
Optional Bluetooth phone integration (ULF module).
Navigation:
Optional factory navigation system with CD-ROM map updates.
Oil Change Interval:
BMW Condition Based Service (CBS) typically recommends oil changes based on driving conditions, often between 10,000-15,000 miles or annually, whichever comes first. Manual may specify fixed intervals or CBS guidance.
Air Filter Replacement:
Every 30,000 miles or as indicated by CBS.
Cabin Filter Replacement:
Annually or every 15,000 miles.
Spark Plug Replacement:
Typically every 60,000 miles for iridium plugs.
Brake Fluid Flush:
Every 2 years, regardless of mileage.
Coolant Flush:
BMW Blue coolant typically has a long service life, often recommended at 5 years or 100,000 miles for initial fill, then every 2-3 years thereafter.
Transmission Fluid Manual:
BMW typically stated 'lifetime' fluid, but many enthusiasts recommend replacement every 60,000-100,000 miles. Manual will detail BMW's official recommendation.
Transmission Fluid Smg:
Hydraulic fluid in SMG system should be checked and potentially flushed according to service intervals.
Differential Fluid Change:
Recommended every 60,000-100,000 miles.
Power Steering Fluid:
Pentosin CHF 11S (same as SMG hydraulic fluid)
Brake Fluid:
DOT 4 High Performance Brake Fluid
S54 Engine Vanos:
Failure of the VANOS system (solenoids, seals, or hub) is a known issue, leading to reduced power and rough idling. Manual will detail diagnostic and repair procedures.
S54 Engine Rod Bearings:
While not as prevalent as on earlier S54 engines, the issue of bearing wear can occur with high mileage or infrequent oil changes. Manual will highlight lubrication system maintenance.
Subframe Cracks:
The rear subframe mounting points are known to crack under stress, particularly on coupes and convertibles. Manual may provide inspection guidance or reinforcement procedures.
Smg System:
SMG pump failure, hydraulic leaks, or gearbox actuator issues can occur. Manual will cover diagnostics and component replacement.
Convertible Top Hydraulics:
Leaks in the hydraulic lines or pump failure affecting convertible top operation are common with age. Manual will detail service and repair.
Actuator Rod Play:
Wear in the actuator rods connecting the engine computer to the individual throttle bodies can cause rough idle or misfires. Manual covers adjustment and replacement.
Bmw M Division:
BMW M GmbH (formerly BMW Motorsport GmbH) has a storied history of producing high-performance versions of BMW's road cars, dating back to the M1 supercar and the legendary M3 E30.
E46 M3 Introduction:
The E46 M3 was introduced for the 2001 model year, replacing the E36 M3. The convertible variant debuted shortly after the coupe.
E46 M3 Convertible Specialties:
The E46 M3 Convertible shared the powerful S54 engine and much of the chassis tuning from its coupe sibling, offering a near-identical performance experience with the added benefit of open-air motoring. The convertible structure required significant reinforcement.
Production Years:
2001-2006
Production Location:
Regensburg, Germany