What Causes Idle Shaking in a New Car?
2 Answers
New car idle shaking can be caused by poor fuel combustion, insufficient ignition energy due to spark plug failure, air intake system leaks or low fuel pressure, poor fuel injector atomization, improper idle adjustment, malfunctioning idle control valve or bypass air valve, carbon buildup on valves and intake ports, etc. Below is an analysis of these causes: 1. Intake manifold or various valve leaks. When unwanted air, fuel vapor, or exhaust gases enter the intake manifold, it causes the air-fuel mixture to become too rich or too lean, leading to abnormal engine combustion. If the leak affects only certain cylinders, the engine may experience more severe shaking, particularly during cold idle. 2. Excessive carbon deposits or dirt on the throttle body and surrounding intake passages can change the cross-sectional area of the air passage, preventing the control unit from precisely regulating idle air intake. This results in an overly rich or lean mixture, causing abnormal combustion and engine shaking.
I recently witnessed the issue of new car idle shaking on my friend's car just a few days ago. His newly purchased car was vibrating noticeably while waiting at a red light. The main causes often lie in the ignition system, such as improperly adjusted spark plug gaps or poor contact in ignition coils leading to uneven combustion. Additionally, fuel injectors in the fuel system might be clogged with impurities - this frequently happens when new cars use low-quality gasoline. Carbon buildup in the idle control valve is another common culprit, as new engines accumulate some debris during the break-in period. Loose engine mounts can also frequently cause shaking sensations that affect driving comfort. I recommend new car owners start with simple troubleshooting, like trying higher-grade fuel from a different gas station. If the problem persists, take it to the dealership for a thorough inspection. Don't underestimate this issue - addressing it early can save you trouble.
