What to Do When a Four-Cylinder Misfires?
4 Answers
For a four-cylinder misfire, it is recommended to inspect the spark plugs, ignition coils, high-voltage wires, fuel injectors, and cylinder pressure of the affected cylinder. The causes of a four-cylinder misfire are as follows: 1. Poor contact or excessive resistance in the ignition coil corresponding to the related cylinder, or a damaged ignition coil. 2. Leakage or open circuit in the cylinder's high-voltage wire, excessively large or small spark plug gaps, or carbon buildup between the electrodes. 3. Airflow. The powertrain control module detects an air flow sensor (MAF) output indicating lower than normal airflow, leading to a lean fuel mixture. 4. Intake system. Air entering the intake system bypasses the air flow sensor, resulting in a lean fuel mixture condition. Check for disconnected or damaged vacuum hoses.
When I encounter a four-cylinder misfire issue, I always start by checking the simpler components first, such as the spark plugs and ignition coils. These parts are prone to failure, often due to carbon buildup or aging, which can lead to poor ignition. I also recommend using an OBD scanner to read the trouble codes—it will specifically indicate which cylinder is having problems, saving you time. If the spark plugs are fine, the next step is to inspect whether the fuel injectors or nozzles are clogged or if the fuel pressure is stable. Don’t forget that poor fuel quality can also cause misfires. Long-term neglect can lead to more severe issues, such as damaging the catalytic converter, which would result in higher repair costs. For safety, once a problem is detected, stop the vehicle and take it to a professional repair shop as soon as possible. Regular maintenance, such as checking these systems every 20,000-30,000 kilometers, can prevent most misfire situations.
I just bought my car and it experienced a four-cylinder misfire, which scared me into immediately shutting it off for inspection. At first, I thought it was a spark plug issue, but even after replacing them, the problem persisted. Later, I discovered that the wiring of the ignition coil was loose, causing unstable current. My advice to car owners is not to tinker blindly. First, observe if any warning lights are illuminated on the dashboard. If there are, it's best to take it to a repair shop to scan for trouble codes with their equipment—it's very accurate. A misfire can cause noticeable engine shaking, poor acceleration, and increased fuel consumption. If ignored, it could damage the exhaust system, leading to a frightening repair bill. From my experience, regular maintenance is key, such as checking spark plugs and coils every few oil changes.
A four-cylinder misfire is no small matter—it could be due to old spark plugs or a faulty coil, and needs immediate attention. I usually start by checking the spark plugs: pull them out and inspect the color; if they're blackened or cracked, replace them right away. Next, test the ignition coil with a multimeter to measure voltage. If left unresolved, the engine will shake violently, performance will drop, and fuel consumption will increase. Don’t delay, or the catalytic converter might fail, which is expensive to replace. Regular maintenance is recommended to keep the system running smoothly.
