What Causes Severe Shaking When Starting a Car?

[AidenMarie]

The reason for severe shaking when starting a car is the wear and slippage of the clutch pressure plate and disc, which can be caused by aging or quality issues. Both the pressure plate and disc need to be replaced simultaneously. Here are some related explanations for starting shake: 1. When the car shakes during startup, let the engine idle. 2. Engage a low gear, slowly release the clutch pedal, and increase the throttle to start. If the body shakes noticeably, it indicates clutch shudder. 3. Clutch shudder can also be caused by broken or loose rivets on the driven plate, fractures in the driven plate steel sheet, or unbalanced rotating components. 4. Loose engine mounts or misalignment between the transmission's first shaft and the engine crankshaft centerline can also lead to car shaking during startup.

[HectorLynn]

I've experienced this situation before, it feels like the car is trembling. The most common cause is clutch issues, especially in manual transmission vehicles, where uneven wear on the clutch disc leads to jerky engagement when starting. Last time my car shook badly during acceleration, and after inspection, it turned out to be worn pressure plate springs, along with an uneven flywheel surface. Faulty spark plug ignition can also cause this - if one of the four cylinders isn't performing properly, it's like walking with a limp. Engine mount deterioration is another culprit, where engine vibrations are directly transmitted to the cabin, making even your phone vibrate inside the car. Don't overlook tire problems either; improper wheel balancing or deformed rims can cause shaking during acceleration due to uneven force distribution. I recommend getting it checked as soon as possible, don't wait until the car completely breaks down before taking action.

[DiPhoebe]

Severe shaking during startup is usually caused by the following reasons: The clutch system abnormality is the main cause. For manual transmissions, wear or burning of the clutch disc, or deformation of the pressure plate can lead to shaking. For automatic transmissions, focus on inspecting the torque converter and oil pump. Aging or failure of engine mounts is also common, as cracked rubber pads significantly reduce vibration damping. Unstable fuel supply from the fuel system can also cause shaking, which may result from clogged fuel injectors or insufficient fuel pump pressure. The most peculiar case I've seen was shaking caused by wear in the driveshaft CV joint, accompanied by a rattling sound. A simple self-test is to start the engine cold, put it in neutral, and press the accelerator. If there's no shaking, it's likely a drivetrain issue. Professional repair requires lifting the transmission, and the labor cost isn't cheap.

[NoahLee]

I know exactly how that feels. When I used to drive a manual transmission car and experienced shaking during startup, I found it was due to operation issues: releasing the clutch too quickly or not matching the throttle properly. After ruling out driving habits, first check the spark plugs and ignition coils, as misfiring cylinders are the most common cause of shaking. Then inspect the clutch three-piece set - if the wear exceeds 2mm, it should be replaced. For automatic transmission cars, pay special attention to the transmission fluid condition, as deteriorated fluid can cause gearshift shocks. Once when helping a friend diagnose startup shaking, it turned out to be caused by an intake manifold leak leading to an overly lean air-fuel mixture. Vehicles frequently used for short trips are prone to carbon buildup, and a dirty throttle body can also cause rough starts. I recommend cleaning the fuel system every 30,000 kilometers.