What causes the car to shake when releasing the throttle while driving?

[Espírito Santo]

Vehicle shaking during acceleration and driving: 1. Possible cause one: The most common fault causing shaking during acceleration is damaged spark plugs. Worn spark plug electrode gaps result in insufficient spark, leading to incomplete combustion of the air-fuel mixture and consequent shaking during acceleration. Additionally, cracks in the ceramic part of the spark plug can prevent sparking, causing one cylinder to stop working and resulting in acceleration shaking. 2. Possible cause two: Poor quality gasoline can lead to inadequate atomization by the fuel injectors, causing incomplete combustion of the air-fuel mixture in the cylinder, which also results in idle shaking. It is recommended to use higher-grade gasoline after finishing the current tank and perform a fuel system cleaning.

[MaxMarie]

As a veteran driver with nearly twenty years of experience, I've encountered this situation several times. When the car shakes while decelerating, it's mostly due to internal engine imbalance—worn-out spark plugs that haven't been replaced in time, for example, can cause unstable ignition and jerking during deceleration. Or, if the throttle body is coated with thick carbon deposits, reduced air intake can lead to uneven air-fuel mixture. Issues in the fuel system, like clogged injectors or an aging fuel pump, can also cause intermittent power delivery. Once, I fixed it myself by cleaning the throttle body—it was straightforward. But be cautious: severe shaking might indicate loose engine mounts, causing the entire engine to wobble, which is a major safety hazard. My advice is to first check the dashboard for warning lights, then visit a professional repair shop for diagnosis. Addressing it early saves money and peace of mind—don’t wait until it breaks down on the road.

[MacReed]

I've been into cars for quite some years now, and the common root cause of shaking is powertrain imbalance. Think about when you let off the gas and the engine RPM drops suddenly—if there's abnormal fuel injection or ignition, it'll become unbalanced. For instance, worn spark plug electrodes can cause intermittent misfires, or a leaking intake manifold sucking in debris leads to insufficient air. Fuel system issues like carbon-clogged injectors causing uneven spray patterns are also frequent culprits. For automatic transmissions, you should also check if the torque converter or clutch is slipping—poor power transfer naturally causes shaking. I've found that regular maintenance really saves trouble: replacing spark plugs every 30,000 km, cleaning the throttle body and intake tract every two years can greatly reduce such issues. Of course, safety first—if anything feels off, immediately have a trusted mechanic check the electrical and mechanical components.

[McEmily]

I also experienced car shaking when releasing the throttle. The reasons could be quite simple, such as aging spark plugs causing poor ignition, leading to insufficient power and shaking when letting off the gas. A dirty throttle body or clogged air filter affecting air intake can also cause engine instability. If there are fuel system issues like low fuel pump pressure or clogged fuel injectors, the car may jerk as well. It's recommended to check if the spark plugs or air filter need replacement, as these are easy to handle. Timely visits to the repair shop can prevent safety hazards.