What are the reasons for severe shaking when a car is just started?

[SanSavannah]

Severe shaking when a car is just started can be caused by: 1. Transmission issues; 2. Problems with the clutch assembly; 3. The clutch pressure plate, pressure springs, and release levers not being on the same plane; 4. Jerky engagement between the transmission gears and drive shaft; 5. Uneven operation among the engine cylinders; 6. A dirty throttle body causing uneven air intake and operation; 7. Broken or burned-out high-voltage wires; 8. Spark plugs failing in some cylinders; 9. Poor tire balance. Body shaking is a common issue many car owners encounter. If noticeable shaking occurs when starting the vehicle or while idling with the engine running, it may indicate a problem that requires prompt inspection.

[MacPresley]

Having driven for so many years, I've encountered numerous instances of engine shaking during startup, with the most common cause being excessive carbon buildup in the throttle body leading to restricted airflow. During cold starts, when the engine oil hasn't warmed up yet and its fluidity is poor, combined with carbon deposits blocking the system and uneven fuel supply from the injectors, the air-fuel mixture burns unevenly, causing the engine to shake violently. Additionally, worn-out spark plugs can lead to unstable ignition, making the shaking even more pronounced. I personally experienced a winter startup where the car shook like an earthquake, and the issue was only resolved after cleaning the carbon deposits and replacing the spark plugs. I recommend avoiding low-quality gasoline and regularly using fuel system cleaners to prevent carbon buildup. Also, the intake system should be inspected, as a dirty air filter can exacerbate the problem. Developing a habit of annual maintenance can help avoid costly repairs and ensure safer, more reliable driving.

[VonSawyer]

The car shakes violently right after starting, which is quite annoying. I think it might be related to low temperatures, especially in winter when the engine oil is too thick and lacks proper lubrication, causing uneven friction among engine components and resulting in shaking. There could also be issues with the fuel system, such as clogged fuel injectors or low fuel pump pressure, leading to insufficient fuel supply and incomplete combustion during startup, which naturally causes shaking. I've experienced a similar situation before—the steering wheel was shaking—and after inspection, it turned out the fuel line was clogged with impurities. Trying a different brand of gasoline or adding a fuel cleaner might help. Another issue not to overlook is carbon buildup; long-term accumulation in the cylinders can cause unstable combustion during startup due to insufficient fuel injection. If the shaking happens frequently, it's best to get it checked by a professional shop promptly to prevent a minor issue from turning into a major problem that affects the driving experience.

[OJake]

When the car shakes violently upon starting, my first thought is that there might be an issue with the spark plugs or ignition coils. After several years of use, aging components can fail to ignite properly, causing uneven combustion during startup and resulting in car shaking. Carbon buildup is another common cause; a dirty throttle body can restrict air intake, leading to a lean air-fuel mixture and increased shaking. Alternatively, an overly rich mixture with too much fuel and insufficient air can also cause unstable combustion. It's recommended that regular car owners periodically replace spark plugs and clean carbon deposits. If the shaking is accompanied by unusual noises, it might indicate worn-out engine mounts that need replacement. Addressing these issues promptly can prevent engine damage, fuel efficiency problems, and safety hazards.

[DiLevi]

The car shakes violently right after starting, which worries me about safety, especially since the steering wheel vibrates severely, affecting control of the vehicle. Possible causes include excessive carbon buildup, a clogged throttle body reducing air intake, or unstable fuel supply from the injectors making combustion difficult. Worn engine mounts can also loosen and cause shaking. I recall similar issues occurring during hot summer months when moisture entered the fuel lines. It's advisable to regularly check the air filter to prevent excessive dirt and dust buildup, which could worsen the problem. Warming up the engine for a minute or two before driving allows the oil to circulate properly. If issues arise, don't delay—take the car to a repair shop for a thorough diagnosis to prevent accidents.