An engine misfire is one of those car problems that can start as a minor annoyance but quickly turn into a serious issue if left unchecked. If you’ve noticed your car hesitating, shaking, or losing power while driving, your engine could be misfiring. While some causes are simple fixes, others could indicate deeper mechanical trouble. Figuring out what’s happening under the hood and taking quick action can save you from costly breakdowns.

What Causes an Engine to Misfire

An engine misfire happens when one or more cylinders fail to ignite properly. This can result in a noticeable loss of power, rough idling, and increased fuel consumption. Several issues can cause misfiring, including problems with the ignition system, fuel delivery, or internal engine components.

One of the most common culprits is worn-out spark plugs. These tiny components create the spark needed to ignite the fuel mixture in the engine. Over time, they can wear down, get covered in carbon deposits, or even crack, leading to inconsistent firing. Faulty ignition coils or damaged plug wires can also cause weak or intermittent sparks, leading to misfires.

Another possible cause is fuel system issues. If your fuel injectors are clogged or failing, they won’t deliver the right amount of fuel to the cylinders, causing an imbalance in combustion. Low fuel pressure from a failing fuel pump or a dirty fuel filter can also prevent the engine from getting the fuel it needs, leading to misfires under acceleration.

Airflow problems are another factor. A dirty air filter or a faulty mass airflow sensor can throw off the engine’s air-fuel ratio, causing cylinders to misfire. In more severe cases, internal engine problems like low compression due to worn piston rings or leaking valves can be the root cause.

Signs Your Engine Is Misfiring

The most obvious sign of an engine misfire is a sudden loss of power or hesitation when accelerating. The engine may feel sluggish, and the car might shake or vibrate more than usual. If the misfire is severe, you might even hear popping or sputtering sounds from the exhaust.

A check engine light is another key indicator. Modern vehicles use onboard diagnostics to detect misfires, and if the system senses a problem, it will trigger the check engine light. A scan tool can help pinpoint which cylinder is misfiring, making diagnosis easier.

Other symptoms include poor fuel economy and excessive exhaust smoke. If your car is burning too much fuel due to a misfire, you may notice a sharp drop in gas mileage. A misfiring engine can also lead to unburned fuel passing through the exhaust system, resulting in smoke or even a noticeable fuel smell.

What to Do If Your Car’s Engine Is Misfiring

If your car is misfiring, the first step is to avoid driving for extended periods until the issue is diagnosed. Continuing to drive with an active misfire can cause damage to the catalytic converter, a costly component responsible for controlling emissions.

Check your spark plugs and ignition coils first. If your spark plugs are old or worn, replacing them might resolve the issue. Ignition coils should also be inspected for cracks or damage. If the issue isn’t with the ignition system, check for fuel delivery problems by inspecting the fuel injectors and fuel filter. A clogged fuel injector can sometimes be cleaned, but if it's damaged, replacement may be necessary.

If the problem persists, it’s best to have a professional inspect your car. More complex issues, like vacuum leaks, faulty sensors, or internal engine problems, require specialized tools and expertise to diagnose properly.

Preventing Future Misfires

Routine maintenance is the best way to prevent engine misfires. Regularly changing your spark plugs, ignition coils, and air filters can keep your engine running efficiently. Using high-quality fuel and occasionally adding fuel system cleaners can help prevent injector clogging.

Keeping an eye on your vehicle’s performance can also help catch early signs of misfires before they become major issues. If your engine ever feels sluggish, your gas mileage drops or your check engine light comes on, don’t ignore it—getting ahead of the problem can save you time and money.

Experiencing engine hesitation or loss of power? Don’t risk further damage to your vehicle! Bring your car to JC Motors in Tualatin, OR, for a full engine diagnostic and expert repairs. Call now to schedule your appointment!