What Causes Multi-Cylinder Misfire?
2 Answers
Multi-cylinder misfire can be caused by the following two main reasons: Faults in the Electronic Control System: Faults in the electronic control system and mechanical components. Electronic control system faults include missing or inaccurate sensor signals, control unit failures leading to incorrect or no signal output, damaged spark plugs or ignition coils causing failure to ignite, fuel injectors not spraying fuel, and connection line faults. Faults in the Mechanical Components: Mechanical faults mainly involve insufficient cylinder pressure, such as valves not sealing tightly, air leakage, excessive clearance between the cylinder, piston, and piston rings, leading to insufficient compression, etc.
Multi-cylinder misfire refers to a situation where multiple cylinders in the engine fail to ignite, causing severe shaking and lack of power when driving. There are many common causes, such as spark plugs that have been used for too long and burned out, or ignition coils that fail to deliver electricity, especially in older car models. The fuel system can also be a major issue, like clogged fuel injectors that can't spray fuel properly, or a fuel pump that lacks sufficient power to deliver fuel on time. A dirty mass airflow sensor can also cause problems by providing inaccurate readings, leading to improper air-fuel mixture for ignition. If the electronic control unit (ECU) malfunctions and sends incorrect signals, multiple cylinders may stop working. These issues not only waste fuel but also make the exhaust smell bad, and they can be particularly dangerous when driving on highways. I've encountered this several times—first, check if the check engine light is on, then use an OBD scanner to read the trouble codes, which often helps pinpoint the specific cylinder or component. If all else fails, take the car to a repair shop promptly, as prolonged neglect can lead to worse engine wear.
