What are the causes of car engine speed fluctuation?
2 Answers
Car engine speed fluctuation can be caused by: 1. Abnormal intake system: Leaks in the intake manifold or various valves can result in either too rich or too lean air-fuel mixture, leading to abnormal engine combustion accompanied by engine shaking; 2. Abnormal fuel system: Excessive carbon deposits and dirt on the throttle valve and surrounding intake passages change the cross-sectional area of the air passage, causing the air-fuel mixture to be too rich or too lean and resulting in abnormal combustion; 3. Unstable idle speed: Long periods without maintenance; 4. Abnormal spark plug system: Incorrect spark plug gap, eroded or damaged spark plug electrodes, or carbon deposits on spark plug electrodes can lead to reduced spark energy, misfires, weak spark pressure, or failure to ignite.
When it comes to engine RPM fluctuation, I've driven many cars and found there are quite a few common causes. For instance, aging spark plugs tend to accumulate carbon deposits after prolonged use, leading to uneven ignition. Another possibility is vacuum leaks in the intake system - loose or cracked pipes can draw in extra air, causing unstable RPM. Clogged fuel injectors are also a frequent issue, as irregular fuel spray affects engine performance. Sometimes, damaged engine mounts can cause noticeable vibrations that make the whole car shake. My advice is to regularly inspect ignition components - simply replacing spark plugs often solves the problem economically. If the shaking becomes severe, don't push your luck; visit a professional repair shop immediately because safety always comes first.
