What causes severe car shaking when the accelerator is pressed hard?

[McGabriel]

Severe car shaking when the accelerator is pressed hard can be caused by the following reasons: 1. Dirty air filter: The air filter is designed to protect the engine and reduce wear, typically requiring replacement around 10,000 kilometers. If not replaced in time, insufficient air intake can lead to low idle speed, causing the engine to shake. Simply replacing the filter can resolve this issue. 2. High-voltage line break: A high-voltage line break refers to a broken conductor core in the high-voltage line, which can affect ignition and cause engine shaking. Use a multimeter to measure resistance and replace the one with significantly higher resistance. 3. Spark plug lifespan: Spark plugs have a limited lifespan. After exceeding 30,000 to 40,000 kilometers, their ignition efficiency noticeably decreases, which can affect ignition. This is the most common issue, and replacing all spark plugs can solve the problem.

[DiElaina]

I also experienced severe shaking when flooring the gas pedal in my old car, and later found out it was due to excessive carbon buildup clogging the throttle body, starving the engine of air. My friend's car had blackened spark plugs causing intermittent ignition and violent vibrations. For vehicles over five years old, cracked and aged engine mount rubber can also cause this issue – the whole body shakes at highway speeds. Once I forgot to replace the air filter, and the clogged filter paper made the car shake like a massage chair under hard acceleration due to insufficient airflow. I recommend checking these basic items first. Usually, cleaning carbon deposits and replacing the three filters during maintenance can solve the problem. Don't wait until the engine misfires – that's when real trouble starts.

[DelKai]

From a maintenance perspective, sudden throttle-induced shaking typically stems from three root causes. First is ignition system issues - excessive spark plug gaps or aging ignition coils causing misfires, leading to incomplete combustion and engine jerking. Second is insufficient fuel supply, often due to clogged injectors or weak fuel pump pressure, particularly common in vehicles using low-quality gasoline long-term. Third involves mechanical component failures, such as broken engine mounts failing to absorb vibrations, or worn CV joints causing drivetrain imbalance. When encountering this issue, it's best to connect diagnostic tools to read trouble codes and use a borescope to inspect cylinder carbon buildup for targeted repairs.

[AmirLee]

A veteran truck driver with 20 years of experience tells you that this issue is 80% caused by poor driving habits. Constant low-speed crawling in urban areas leads to engine carbon buildup like plaster on a wall, causing air-fuel mixture ratios to go haywire when suddenly flooring the throttle. Manual transmission vehicles may jerk if the clutch is released too quickly, while automatics suffer from delayed transmission valve body oil pressure. Remember to take monthly highway trips to rev the engine and add a bottle of fuel system cleaner during refueling. Since adopting these habits, my fleet has never experienced vibration issues again.