What Causes Shaking After Startup?
2 Answers
Reasons for shaking after startup: 1. Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor; 2. Aging engine mounts; 3. Dirty throttle body or excessive carbon buildup in the fuel injectors, leading to an overly lean air-fuel mixture during cold starts; 4. Abnormal engine coolant temperature; 5. Low engine cylinder pressure. Engine maintenance tips: 1. If the vehicle is only driven in urban areas, the air filter may not get clogged, but if driven on dusty roads, pay special attention to cleaning the air filter; 2. Remove sludge from the throttle body; 3. Clean carbon deposits from the fuel injectors, as the combustion chamber is prone to carbon buildup, which can cause starting difficulties. Carbon deposits in the fuel injectors can also lead to clogged fuel passages, distorted fuel spray, and poor atomization.
I've also experienced the car shaking after starting a few times, and each time it felt like the engine was vibrating intensely. From my experience, the most common causes are aging spark plugs or carbon buildup. If spark plugs have been used for too long, the ignition becomes uneven, causing the engine to shake. Another reason could be clogged fuel injectors, as uneven fuel spray disrupts the air-fuel mixture, especially noticeable during cold starts. Fuel system issues, such as a failing low-pressure fuel pump, can also lead to unstable fuel supply and cause shaking. A dirty air filter restricting airflow can make the engine 'struggle to breathe,' resulting in vibrations. If left unaddressed, the shaking may worsen and even damage other components. Therefore, it's best to get it checked early—scan for trouble codes or simply try replacing the spark plugs first.
