What Causes Engine Misfire in Cars?

[AngeloAnn]

Engine misfire in cars is caused by: 1. Air leakage due to poor sealing of pistons, cylinder walls, valves, or valve seats, leading to excessively low cylinder pressure; 2. Severe burning of distributor cap contacts in the ignition system; 3. Air leakage in pipelines allowing air to enter the cylinder through leaking pipes, causing the engine to malfunction; 4. Excessive carbon buildup due to low heat value of spark plugs, leading to spark plug leakage, weak sparking, or non-functioning spark plugs; 5. Clogged fuel injectors with carbon deposits preventing precise injection and atomization, which can easily cause the injectors to stick and result in engine misfire.

[OIsaac]

I've experienced engine misfires several times, and the most common cause is ignition system failure. For example, worn-out spark plugs or faulty ignition coils can prevent a cylinder from firing. Clogged or dirty fuel injectors can also lead to insufficient fuel supply, resulting in a misfire. Once, my car was shaking violently, and upon inspection, it turned out to be poor electrical contact—either loose wiring or an ECU issue. More severe cases involve insufficient internal engine compression, such as worn piston rings or leaking valves, which would require a major overhaul. Misfires can reduce power, increase fuel consumption, and if not repaired promptly, can damage the catalytic converter or even cause severe engine shaking, making it dangerous to drive. During regular maintenance, pay attention to the condition of spark plugs and fuel injectors, and address any issues early to prevent minor problems from escalating.

[SophieFitz]

During car repairs, I've encountered various cases of engine misfires with diverse root causes. In the ignition system, spark plugs may break when they reach the end of their lifespan, and ignition coils can burn out, preventing ignition altogether. In the fuel injection system, clogged injectors can cause uneven fuel supply, or dirty fuel lines may affect injection. Compression issues like insufficient cylinder pressure stem from piston wear or poor valve sealing. Electrical faults include short circuits, open circuits, and even ECU signal interference causing problems. When detecting an engine misfire, I use a diagnostic tool to read fault codes for localization, then proceed with step-by-step testing for resolution. Don't ignore minor symptoms - prolonged misfiring can lead to overall engine imbalance, skyrocketing fuel consumption, and even catalytic converter failure.

[QuinnMarie]

Last time my car was shaking, it was due to a misfiring cylinder. The troubleshooting is straightforward: the most common cause is burnt spark plugs, and replacing them can restore performance immediately. Alternatively, the fuel injectors might need cleaning, as poor fuel quality can lead to carbon buildup. Electrical issues, such as damaged wires grounding out, can also interrupt operation. Loss of engine compression is rare, but older cars with worn piston rings are at risk. After a misfire, you'll notice a significant drop in power, making it difficult to overtake on the highway—prompt inspection is advised. Regular maintenance, like changing spark plugs, can prevent this. Don't skimp on small expenses and risk bigger problems.