Why does the car shake a little when starting?

[Shelby]

Car shaking after starting may be caused by the following reasons: 1. Unstable oil pressure: Abnormal fuel pump supply pressure or incorrect readings and poor performance of the intake pressure sensor can cause body shaking. 2. Aging engine components: Car shaking is also related to aging engine mounts, which transmit vibrations to the steering wheel and cabin, causing shaking at idle. 3. Severe engine carbon buildup: The most common cause of car shaking is a dirty throttle or excessive carbon deposits on the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making it difficult to start.

[MacAaron]

Last time I started my car, it shook violently, which really scared me. Later, I found out it was due to unstable idling, possibly caused by uneven ignition from worn spark plugs or abnormal combustion due to faulty ignition coils. If the engine mounts are loose, the vibration can also worsen the shaking. This issue is more common in cold weather because the engine oil viscosity is higher. I think it's best not to delay and to check the fuel system and air filter right away to prevent a small problem from becoming a big one. Replacing the parts at a repair shop can solve the issue—it's a pretty common fault that regular maintenance can help prevent.

[DiChloe]

As a DIY car maintenance enthusiast, I believe that engine shaking during startup is mostly caused by fuel supply or ignition system issues. Insufficient fuel pump pressure can lead to engine power loss, and clogged fuel injectors can also cause trembling. Worn-out spark plugs need timely replacement. A faulty mass airflow sensor may also result in unstable idling. When troubleshooting, start with the basics—check fuses and wiring connections before jumping into major repairs. Pay extra attention to using the correct oil grade for cold-start shaking. In short, address the issue early for safety; if it's beyond your skills, take it to a professional shop.

[PaisleyRose]

Having driven for many years, common causes of startup shaking include a dirty throttle body or a malfunctioning idle control valve, which can be resolved by cleaning. Issues with spark plugs or ignition coils are also not uncommon, so check for wear. If the engine mounts are aged, they can amplify the vibration sensation. Don't wait for it to worsen; getting it fixed at a quick repair shop is straightforward.