What Causes Car Engine Vibration?
2 Answers
The causes of car engine vibration are: 1. Dirty throttle body or excessive carbon buildup in fuel injectors; 2. Ignition system issues - it's necessary to check the working condition of spark plugs, high-voltage wires, and ignition coils. Poor ignition system performance or inadequate spark plug firing can also lead to such faults; 3. Unstable fuel pressure - if you've already cleaned engine carbon deposits, cleaned the throttle body, replaced gaskets and spark plugs but still observe body vibration at idle, visit a 4S shop to check fuel supply pressure and whether the intake pressure sensor is normal; 4. Aging engine components - car vibration may also relate to worn engine mounts. Engine mounts serve as the vibration absorption system for engines, absorbing minor vibrations during operation. If engine mounts fail, these vibrations will transmit to the steering wheel and cabin, causing noticeable shaking at idle.
I often encounter car owners asking about engine shaking issues. Let me briefly explain a few common situations. Engine shaking is usually closely related to ignition system failures. After spark plugs have been used for 30,000-40,000 kilometers, electrode wear can cause insufficient ignition energy, leading to individual cylinders not working properly, and you can clearly feel the steering wheel shaking. Another often overlooked issue is carbon buildup. Long-term low-speed city driving can cause carbon deposits on the throttle body and fuel injectors, resulting in uneven combustion of the air-fuel mixture, especially noticeable during cold starts. Additionally, aging engine mount bushings—rubber components that harden and crack after five or six years—lose their cushioning effect, allowing engine vibrations to transfer directly to the car body. Problems in the fuel system can also cause shaking, such as a clogged fuel filter or insufficient fuel pump pressure, leading to unstable fuel injection and affecting power output. Finally, pay attention to ignition coil failures and vacuum hose leaks—the former can cause misfires, while the latter affects air intake. If you notice shaking, it's best to get it checked early, as small issues left unattended can eventually damage the engine.
