The P0304 code in your 2024 BMW 3 Series indicates the engine control module has detected persistent misfires in cylinder 4. BMW's turbocharged engines demand precise combustion for their renowned driving dynamics, making effective diagnosis essential for restoring performance.
Understanding P0304 in the 2024 3 Series
The 2024 3 Series offers the B48 2.0L turbocharged four-cylinder in 330i models and the B58 3.0L turbocharged inline-six in M340i variants. For the four-cylinder, cylinder 4 is at the rear position. For the inline-six, it's in the middle-rear of the cylinder bank. Both engines use direct injection and turbocharging demanding quality ignition components.
BMW Turbo Engine Considerations
BMW's turbocharged engines operate under elevated pressures requiring robust ignition systems. Spark plugs must reliably ignite compressed charges. Ignition coils face demanding duty cycles. Direct injection contributes to carbon accumulation on intake valves—a known BMW concern addressed through periodic cleaning. The sport-tuned nature means misfires significantly affect driving character.
Diagnostic Approach
Identify your engine—B48 four-cylinder or B58 six-cylinder. Use BMW-compatible diagnostic equipment for full code and freeze frame data. Access cylinder 4 noting engine-specific location. Test ignition coil output and spark plug condition. Verify fuel injector operation. Consider carbon buildup inspection for higher-mileage vehicles.
Repair Solutions
Install BMW-specified spark plugs appropriate for your engine. Replace degraded ignition coils. Address carbon buildup through walnut blasting or chemical cleaning. BMW's driving character depends on quality repairs.