What Causes Idle Shaking, Lack of Power During Acceleration, and Jerking?
3 Answers
Here are the possible reasons for idle shaking, lack of power during acceleration, and jerking: 1. Spark plug electrode erosion Severe erosion of spark plug electrodes, high-voltage wire leakage, or carbon buildup in the throttle body may be the cause. If the oxygen sensor malfunctions, it will affect the electronic fuel injection system, leading to idle shaking, lack of power during acceleration, and jerking. 2. Regular inspection: If the car exhibits shaking at idle or lack of power during acceleration, it indicates a fault in the engine system. The first step should be to inspect the condition of critical engine components, especially those affecting the ignition system, such as spark plugs. During daily driving, it is essential to regularly check the condition of car components and replace faulty parts promptly to maintain optimal performance.
Last time my car was shaking like a massage chair, and the acceleration was jerky. After towing it to the repair shop and checking for a long time, the mechanic said the main issue was with the ignition system. The spark plugs hadn't been replaced after 40,000 kilometers, and the electrodes were worn out, causing unstable ignition. The ignition coil also had a crack, leaking electricity on rainy days. During the repair, they also found the throttle body was caked with carbon deposits, like the bottom of a pot, leading to insufficient air intake and weak acceleration. Now, every 20,000 kilometers, I have the mechanic clean the carbon deposits, and the problem hasn't recurred. Such issues shouldn't be delayed, as they might cause the car to break down halfway, which would be even more troublesome.
I've repaired many cars with similar issues. The most common causes of idle shaking and acceleration hesitation fall into three categories. First, fuel system problems - clogged injectors due to varnish buildup or a dirty fuel filter restricting fuel flow. Second, ignition issues - leaking ignition coils or excessive spark plug gap affecting combustion. Third, mechanical faults - worn engine mounts failing to dampen vibrations, or stretched timing chains causing misfires. There was one special case recently where a car owner used cheap, low-quality fuel that completely clogged the catalytic converter. My advice is to first read the trouble codes before conducting targeted diagnostics - don't waste money randomly replacing parts.
