What Causes Car Shaking During Cold Start?
2 Answers
Cold start body shaking has the following reasons: 1. The main reason is incomplete fuel combustion: resulting in insufficient power output. 2. Low ignition energy: During startup, especially when fuel and lubricant temperatures are low, revving the throttle is required to meet power demands. Over time, the electrode gap of spark plugs gradually increases, leading to reduced ignition energy and poor fuel atomization, consequently causing body shaking. 3. Aging ignition coils, or aging/sparking high-voltage wires of spark plugs: resulting in decreased ignition energy and subsequent body shaking.
As someone who frequently tinkers with cars, let's talk about cold start shaking. The most common reason for rough engine operation at low temperatures is issues with the ignition system, such as aging spark plugs or excessive carbon buildup, leading to inaccurate ignition timing and noticeable shaking. The fuel system also plays a role—clogged fuel injectors causing uneven air-fuel mixture or insufficient fuel pump pressure affecting fuel supply. Another factor is aging or loose engine mounts failing to dampen vibrations. Additionally, sensors like the oxygen sensor or a sticky idle control valve might mislead the computer's adjustments. The air system shouldn't be overlooked either—a clogged air filter restricting intake or leaks in the intake pipe can cause issues. It's recommended to first check the spark plugs' condition, replace them regularly, and clean carbon deposits; pay attention to using the right oil viscosity during seasonal changes; if idle is unstable, try cleaning the throttle body. Best not to tough it out—get a professional inspection early to avoid worsening engine wear.
