What Causes Engine Idle Shaking and Lack of Power During Acceleration?
2 Answers
Reasons for engine idle shaking and lack of power during acceleration: Excessive carbon buildup in the throttle body leading to restricted air intake. As carbon deposits accumulate, fuel passages become blocked, engine performance declines, fuel consumption increases, and a series of complications may follow. Gasoline is refined from heavy oil with high sulfur and acid content, containing elevated levels of sulfur, carbon, manganese, and trace metals. High-impurity gasoline leaves sticky residues on combustion surfaces after burning, forming carbon deposits on piston tops and combustion chamber walls. There are primarily two methods to remove carbon deposits: 1. Manual cleaning of internal carbon buildup; 2. Using fuel additives to improve combustion and clean carbon deposits. Manual cleaning requires engine disassembly, which is complex and potentially damaging to the engine.
Last time my buddy's car was shaking like this, it turned out to be an issue with the ignition system. If the spark plugs are worn out or the gap is incorrect, the ignition becomes weak; if the ignition coils are damaged or the high-tension wires are faulty, the ignition becomes even more unreliable. These can all cause a cylinder to misfire, and an engine running on fewer cylinders will naturally shake badly. A severely dirty throttle body can also lead to poor airflow, unstable idling, and weak acceleration. If the engine oil hasn't been changed for too long, it can become sludge-like, or if the catalytic converter is mostly clogged, it can affect exhaust flow. A clogged air filter can also suffocate the engine, leading to insufficient air intake and poor performance. Older cars especially need their engine mounts checked—if they're worn out, the engine won't stay in place and will shake. The worst is if the oxygen sensor fails, causing incorrect fuel injection commands, skyrocketing fuel consumption, and a lack of power. Better get it checked out soon.
