What are the reasons for severe engine shaking in a sedan?
4 Answers
There are four main reasons for severe engine shaking in a sedan: 1. Ignition system failure. Solution: Check if the spark plugs have excessive carbon buildup, and clean or replace them immediately if necessary. 2. Worn or loose engine mounts. Solution: Replace the engine mounts. 3. Carbon deposit issues. Solution: It is recommended to take the car to a 4S shop for engine cleaning. 4. Poor fuel quality. Solution: Clean the car's throttle body promptly. If the issue persists, take the car to a 4S shop for repair. Always refuel at reputable gas stations, use the fuel grade specified by the manufacturer, and perform regular maintenance.
Speaking of that time when my sedan's engine was shaking badly, it was really a headache. I was driving in the city waiting at a red light when the car suddenly started shaking violently, the whole car was rocking, it felt like being on a massage chair. Later, when I took it to the repair shop for inspection, they found that the uneven ignition caused by aging spark plugs was the issue, with one cylinder not working leading to the shaking. The mechanic said other common causes include faulty ignition coils, clogged fuel injectors or insufficient fuel supply from the fuel pump, and a dirty throttle body affecting air intake. If the shaking occurs during cold starts, it might be due to excessive carbon buildup. You can do a simple check yourself to see if the spark plugs have turned black or have oil stains, or listen for any abnormal sounds from the engine. If the shaking is severe, don't push through it, as it can worsen engine wear—get a professional diagnosis and repair immediately, replacing the parts is just a matter of a few tens of dollars.
When the engine shakes severely, I follow a step-by-step troubleshooting process. First, I check the ignition system, as worn or damaged spark plugs are often the main culprit, since misfiring cylinders directly cause unstable power output. Next, I inspect the fuel system, as clogged fuel injectors or a dirty fuel filter can affect fuel delivery. The third step is examining the intake system—excessive dust in the air filter or carbon buildup in the throttle body may restrict airflow. Don’t forget to check the engine mounts for wear; if the damping fails, the engine will vibrate. I typically start by using an OBD scanner to read fault codes. If none are found, I proceed with manual checks. Regular maintenance, like cleaning the throttle body and changing the oil every six months, helps prevent many vibration issues.
Engine shaking in my car mostly stems from several common causes. First is ignition system failure, such as expired spark plug lifespan or damaged ignition coils, leading to misfiring in a cylinder. Second is fuel system issues, where clogged fuel injectors or insufficient fuel pressure affect combustion efficiency. Sensor abnormalities like a failed oxygen sensor can also cause inaccurate control. Mechanical components such as aged engine mounts or severe carbon buildup inside valves may also induce shaking. When encountering severe shaking, remember to turn off the AC to reduce load and drive smoothly to a repair shop for safer and more reliable diagnostics.
