What are the causes of engine vibration?

[VanTanner]

Engine vibration can be caused by: 1. Worn or loose engine mounts; 2. Excessive carbon deposits inside the engine reducing ignition energy; 3. One or more cylinders not functioning properly; 4. Using incompatible fuel octane ratings; 5. Partial blockage of the fuel filter or fuel line between the fuel tank and carburetor. An engine is a machine that converts other forms of energy into mechanical energy, including internal combustion engines, external combustion engines, jet engines, electric motors, etc. For example, an internal combustion engine typically converts chemical energy into mechanical energy. The term engine can refer to either the power-generating device or the entire machine including the power unit, such as gasoline engines and aircraft engines.

[DiHarmony]

I've been driving for over 20 years and have encountered engine shaking several times. The most common causes are aging spark plugs or faulty ignition coils, which can lead to a cylinder misfiring and make the car noticeably shudder. Another frequent issue is the deterioration or cracking of the engine mount rubber pads, especially noticeable when idling with the AC on and in D gear at a red light—it feels like the entire steering wheel is shaking. Fuel system problems are also quite common; for instance, clogged fuel injectors or a dirty fuel filter can cause poor fuel delivery, making the engine sputter. Additionally, excessive carbon buildup can cause shaking, particularly when the throttle body is dirty or there's severe valve carbon deposits, leading to very unstable idling. I recommend first checking the spark plugs and ignition system, then inspecting the engine mounts, as these are relatively easy to address.

[VanJace]

Anyone who's into car modifications knows that engine vibration could be a tuning issue. For example, after ECU remapping, if the fuel injection quantity or ignition timing isn't set properly, causing incomplete combustion of the air-fuel mixture, the car will shake violently. Last time I upgraded to a larger throttle body, it also caused shaking because the increased air intake wasn't matched with corresponding fuel injection. Another case is when modified exhaust systems lead to insufficient backpressure, resulting in reduced low-speed torque and noticeable engine vibration. Additionally, if reinforced clutch plates are too stiff, the vibration during semi-engaged state intensifies, feeling like starting a manual transmission car. That's why modifications shouldn't just focus on speed - balance is crucial. Otherwise, you'll not only deal with vibration but also risk damaging the engine.

[Lima]

As a woman, the thing I fear most while driving is encountering shaking. Last time I started the car, the body shook so much it scared me. The after-sales service said it might be carbon buildup in the throttle body, which is common with a lot of city driving, and a single cleaning should fix it. Also, the spark plugs had reached the end of their lifespan—the manual recommends replacement at 40,000 kilometers, and I exceeded that by a few thousand kilometers before issues arose. Fuel quality also plays a role; using the wrong octane rating or poor-quality fuel from small gas stations can cause abnormal combustion. If the air filter hasn’t been replaced for too long and gets clogged, insufficient air intake can make the engine struggle. They recommended regularly cleaning carbon deposits and replacing the three filters during maintenance. Shaking is often the result of minor issues accumulating, so addressing them early saves hassle.