Reasons for Car Engine Shaking During Cold Start?
4 Answers
Engine shaking during cold start can be attributed to the following reasons: 1. Low ignition energy at low engine temperatures. 2. Inappropriate air-fuel mixture ratio in the engine. 3. Carbon deposits on engine valves and intake passages. 4. Uneven operating conditions among engine cylinders. 5. Malfunctioning coolant temperature sensor. 6. Other factors: Dirty throttle body or mass air flow sensor reducing air intake; Poor operation of EGR (Exhaust Gas Recirculation) valve introducing exhaust gases during idle; Idle air control valve regulating bypass intake passage may not function properly due to low voltage; Poor fuel quality failing to achieve required calorific value, resulting in reduced combustion power output.
Engine shaking during cold starts is quite common, and I think in most cases it's due to ignition system issues—worn-out spark plugs, excessive carbon buildup causing unstable sparks during ignition, leading to engine shaking; or clogged fuel injectors preventing even fuel distribution into the cylinders, resulting in uneven combustion and vibrations. It's more noticeable in cold temperatures because the oil viscosity increases, lubrication effectiveness decreases, and engine friction rises. Additionally, if the mass airflow sensor is dirty, obstructing smooth air intake, it can affect the air-fuel mixture ratio. I recommend regularly replacing spark plugs, cleaning throttle body carbon deposits, using low-viscosity oil in winter, and preheating for a few seconds before starting. Addressing these promptly can prevent increased fuel consumption or severe engine wear, extending your car's lifespan.
My car has been running for a few years, and it shakes violently when starting in winter. Once, a mechanic told me that common causes include insufficient fuel pump pressure leading to inadequate fuel supply, or spark plugs that have been used for too long and fail to ignite. Low temperatures can also thicken the engine oil, making it harder to start. Another possibility is sensor issues, such as a dirty oxygen sensor causing inaccurate computer adjustments and resulting in shaking. From personal experience, if left unrepaired, the problem worsens over time, leading to increased fuel consumption. Now, I pay attention to maintenance: checking the fuel injectors quarterly, using additives to clean carbon deposits, and keeping the battery fully charged. These simple steps ensure stable starts and save a lot on repair costs.
I was startled by the engine shaking during a cold start right after driving. The reasons are simple: the most common causes are aging spark plugs or severe carbon buildup leading to delayed ignition; clogged fuel injection system affecting fuel supply; insufficient battery power, which is weaker in winter. Poor lubrication at low temperatures results in increased friction. Recommendations: replace with new spark plugs, check if the air filter is dirty, and use the appropriate engine oil for maintenance. Addressing these points can basically solve the problem and prevent further damage.
