The reasons why the car shakes while driving include the following: 1. Severe engine carbon buildup causing body vibration: The most common cause of car shaking is a dirty throttle or severe carbon buildup on the engine fuel injectors. After starting the car, gasoline adsorbed on the carbon deposits is sucked into the engine cylinders for combustion, resulting in uneven air-fuel mixture and causing the car to shake at idle after a cold start. The solution is to clean the fuel system and check the idle control valve for carbon buildup, cleaning it promptly if necessary. 2. Ignition system failure: This is also a major reason for body vibration at idle. If there are issues with the spark plugs, high-voltage wires, or ignition coils, the car body will shake when starting. Check if the spark plugs have too much carbon buildup and replace them with new ones if needed. 3. Brake rotors: Brake rotors and brake pads are both crucial components of the braking system. Although brake rotors have a longer lifespan than brake pads, they are more prone to deep grooves and scratches, which require timely replacement to avoid affecting the car's comfort. 4. Unstable oil pressure: Abnormal fuel pump pressure or incorrect readings and malfunctions of the intake pressure sensor can also cause body vibration. Check the oil pressure and troubleshoot step by step, replacing faulty parts if necessary. 5. Aging engine components: Aging engine parts can also cause car vibration. When engine components fail, these vibrations can be transmitted to the steering wheel and cabin, resulting in shaking at idle. Inspect the engine, identify the problematic parts, and replace them. 6. Fuel filter: Cleaning the fuel filter is part of routine car maintenance. Although the fuel filter has a long maintenance cycle and is easily overlooked, once it becomes clogged—especially after driving on dusty roads—it can obstruct the fuel flow, leading to car vibration.
