What Causes Engine Shaking in Cars Sometimes?
2 Answers
Common causes of engine shaking include the following: 1. Engine misfire: This mainly refers to one or more cylinders in the engine not functioning properly. Symptoms typically include intermittent exhaust flow, noticeable shaking of the exhaust pipe, and a distinct engine vibration, sometimes accompanied by a sputtering sound. This is often related to ignition coil failure. 2. Worn or loose engine mounts: Engine mounts are rubber blocks placed between the engine and the frame. Their purpose is to reduce vibrations and absorb shocks during engine operation while securing the engine in place. If these mounts become worn or loose, engine vibration can become significantly worse. Replacing the engine mounts usually improves the situation. 3. Carbon buildup: Carbon buildup is an unavoidable issue in cars, including deposits in the cylinders, throttle body, spark plugs, and intake system. Excessive carbon buildup inside the engine can affect ignition energy, air intake efficiency, and the air-fuel mixture ratio, leading to unstable power output and noticeable shaking during idling and acceleration. It is recommended to have the engine cleaned at a 4S shop. 4. Fuel system issues: Using an inappropriate fuel grade (e.g., filling 93-octane fuel with 90-octane) can reduce engine power and performance. Alternatively, blockages in the fuel tank vent, fuel tank switch, fuel filter, or fuel lines between the tank and carburetor can restrict fuel supply, resulting in a lean air-fuel mixture and engine shaking. It is advisable to use the manufacturer-recommended fuel grade and perform regular maintenance.
I've been driving for ten years and have experienced severe engine shaking before, which felt like sitting on a massage chair. The main causes are usually worn-out spark plugs or faulty ignition coils, leading to inconsistent ignition. Carbon buildup is also a common issue; a dirty throttle body affects air intake, causing uneven combustion and shaking. Another possibility is clogged fuel injectors, resulting in unstable fuel supply. During regular maintenance, it's important to replace spark plugs periodically—typically, they should be checked every 20,000 kilometers. If carbon buildup is excessive, cleaning is necessary; otherwise, the problem will worsen. Additionally, loose engine mounts can cause abnormal vibrations, but that's a mechanical issue, different from internal faults. I remember once ignoring the shaking, and the repair later was quite expensive. Now, I make it a habit to check the engine every month.
