What Causes Engine Shaking After Car Shutdown?
2 Answers
Engine shaking after car shutdown indicates a malfunction in the vehicle. Here are some possible reasons for engine shaking: 1. Engine misfire: This mainly refers to one or more cylinders in the engine not working properly. Common symptoms include intermittent exhaust flow, severe shaking of the exhaust pipe, noticeable engine vibration, and 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 to reduce vibration and cushion the engine's operation, as well as to secure the engine. Once these mounts become worn or loose, the engine's shaking will become significantly worse. Replacing the engine mounts can greatly reduce this issue. 3. Carbon buildup: Carbon deposits can accumulate in the cylinders, throttle body, spark plugs, and intake system. Excessive carbon buildup inside the engine can affect the ignition energy, air intake efficiency, and air-fuel mixture ratio, leading to unstable power output and shaking during idling and acceleration. It is recommended to have the engine cleaned at a 4S shop to address this problem.
I've been driving for over a decade and often encounter situations where the engine still shudders after the car is turned off. It's mostly due to aged or cracked engine mounts. Those things are supposed to firmly support the engine, but when they wear out, the inertia causes the engine to shake a few times when parked. You should check if the rubber on the mounts is cracked or loose. Another common issue is the cooling fan not stopping immediately, continuing to hum and causing slight engine vibrations—it should quiet down in about ten seconds. If the fan keeps running, there might be a problem with the control module. Don’t underestimate this; over time, it can accelerate component wear, and repairs can cost a few hundred bucks. Last time, I went to the shop to replace a mount and had the fan system checked—now it runs smoothly. Always pay attention to the condition of these support components during regular maintenance.
