What Are the Reasons for Severe Car Vibration?
4 Answers
Severe car vibration can be caused by: 1. Ignition system issues: If there is a malfunction in the car's ignition system, it can lead to poor ignition system performance, weak spark plug firing, and other problems, resulting in unstable idling; 2. Worn or loose engine mounts: Engine mounts are rubber blocks placed between the engine and the car frame; 3. Carbon buildup: Carbon deposits can accumulate in the cylinders, throttle body, spark plugs, and intake system. When there is excessive carbon buildup inside the engine, it affects the ignition energy, air intake efficiency, and air-fuel mixture ratio, leading to unstable power output and causing vibrations during idling and acceleration.
Last time my car shook like a massage chair, so I rushed to get it checked. Severe engine carbon buildup is a common cause, especially for cars frequently driven in urban areas. Worn-out spark plugs can also cause shaking - they should be replaced when needed, typically requiring inspection every 40,000 km. Incorrect tire balancing or deformed rims will cause severe shaking at high speeds. If the engine mount rubber is aged, the entire steering wheel will vibrate; this component buffers engine vibrations, and rubber parts generally last no more than six years. A dirty throttle body or poor fuel quality can also cause shaking - switching from 92-octane to 95-octane gasoline might help. If the idle shaking is particularly bad, it could be a faulty ignition coil. Never ignore shaking - checking these four areas first is always the right approach.
I always worry my old car will fall apart when it shakes, so I've studied the vibration issue carefully. Clogged fuel lines are the most annoying - dirty injectors cause unstable fuel supply, try adding a bottle of cleaner. Air intake leaks are also common, often caused by aging manifold gaskets. Incorrect ignition timing is more troublesome, requiring timing belt adjustment. Tire issues are most easily overlooked - unbalanced tires wobble like dancing, especially the front ones. Worn universal joints on the driveshaft cause shaking during acceleration/deceleration. Warped brake discs from hard braking create uneven surfaces that vibrate. Worn stabilizer bar bushings make the car shake over bumps, but these are cheap to replace. Always inspect from simplest to most complex issues to save time and money.
When I first started driving, I didn't understand the reasons for car shaking. Later, I figured out a few points myself. Most cold start shaking in winter is due to overly thick engine oil; switching to lower viscosity oil helps. The most serious issue is collapsed engine mount bushings - the whole car shakes when accelerating. Automatic transmission gear shift jerks feel like being kicked, requiring checks on transmission fluid and valve body. Incorrect air-fuel mixture concentration can also cause shaking, possibly due to clogged air filters or faulty oxygen sensors. Using the wrong gasoline grade makes the engine protest - putting 95 in a car designed for 92 is actually worse. Prolonged low-speed driving causes more carbon buildup; occasional highway driving can improve this. For older cars, shaking is 80% due to part aging - replace them when needed without hesitation.
