What Causes Car Engine Shaking?
3 Answers
Car engine shaking can be caused by: 1. A dirty engine throttle or excessive carbon buildup in the fuel injector, where the gasoline sprayed by the cold-start injector is largely absorbed by carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and difficulty in ignition; 2. Poor performance of the ignition system, including spark plugs, high-voltage wires, and ignition coils; 3. Abnormal fuel supply pressure, incorrect intake pressure readings, or malfunctioning sensors. Solutions for car engine shaking: 1. Clean the fuel system and inspect the idle control valve for carbon buildup; 2. Check if the spark plugs have excessive carbon deposits and replace them if necessary; 3. Inspect fuel pressure and replace faulty components.
My car's engine was shaking like a sieve not long ago. I've researched it myself for a long time and consulted several mechanics. Actually, the main causes boil down to these categories: The most common issue is with the ignition system—spark plugs aging or ignition coils failing, causing a cylinder to stop working. Then there's the intake and exhaust system; the throttle body gets clogged with carbon deposits, gasping for air like an asthma patient, and clogged fuel injectors disrupt smooth fuel supply. If the fuel pump delivers unstable fuel, the engine trembles from starvation. Worn engine mounts also share the blame—when damping fails, the entire steering wheel dances. Additionally, a dirty mass airflow sensor giving inaccurate readings or vacuum tube leaks can all make the engine work uncoordinated. My advice? Start by checking the spark plugs, then clean carbon deposits. For mount issues, just shake the engine by hand to test.
Having driven for decades, I've encountered engine shaking at least a dozen times. The most common cause is misfiring - when one of the four cylinders fails to ignite, the shaking becomes noticeably severe. Spark plugs should be replaced when they reach the end of their lifespan; don't wait until the filament melts to regret it. Excessive carbon buildup in the throttle body can jam the valve, leading to insufficient air intake and unstable combustion. Engine mount deterioration is quite insidious - once the rubber cracks, the damping effect disappears, and even the dashboard can vibrate. The fuel system also demands attention: clogged injectors or aging fuel pump coils causing intermittent fuel supply can be particularly troublesome. Oil contamination on the mass airflow sensor affects data accuracy, and vacuum rubber tubes in older vehicles are prone to cracking and air leaks. I recommend cleaning the throttle body every 20,000 kilometers and addressing any shaking immediately rather than enduring it.
