Why does the car shake when starting cold in winter?

[GenesisLynn]

Cold start shaking in cars can be attributed to the following reasons: 1. Low temperature: The engine temperature is insufficient, and both fuel and lubricant temperatures are too low. During cold starts, additional fuel injection is required to meet power demands. Larger spark plug gaps result in smaller ignition energy. Poor fuel atomization at low temperatures demands higher ignition energy. Prolonged vehicle use can enlarge spark plug gaps, reducing ignition energy and consequently affecting power performance, leading to shaking. 2. Incorrect air-fuel mixture ratio: Inaccurate fuel-air mixture ratio occurs in both open-loop and closed-loop control systems. In closed-loop controlled vehicles, the oxygen sensor's minimum operating temperature is 370°C. If the exhaust pipe temperature hasn't reached 370°C upon startup, the oxygen sensor won't function. This causes the ECU to make incorrect judgments, leading to errors in controlling the fuel-air mixture and ignition timing through actuators, thereby reducing power output and causing shaking. 3. Faulty coolant temperature sensor: The coolant temperature sensor is crucial for the ECU to determine engine operating conditions. If the engine starts at -10°C but the ECU calculates fuel injection based on 20°C conditions, the insufficient fuel quantity will naturally cause shaking.

[SaraFitz]

I have a good understanding of the phenomenon of car engine shaking during cold starts in winter, which mostly occurs in low-temperature environments. Low temperatures can cause engine oil to become thicker and less fluid, increasing the friction resistance of pistons and crankshafts, leading to rough starts. At the same time, if spark plugs are carbon-fouled or aged, their ignition efficiency decreases, causing uneven fuel combustion and resulting in shaking. The vehicle's battery also suffers reduced discharge performance in cold weather, failing to provide sufficient power to the starting system, which further exacerbates vibrations. Additionally, temperature sensors might misread data, leading to an imbalanced air-fuel mixture. I recommend using low-viscosity synthetic oils like 0W or 5W to improve fluidity, regularly inspecting and replacing spark plugs, and preheating the engine for a minute or two before starting. Ignoring this issue can accelerate wear on engine components, so regular maintenance is key. During winter, parking in a garage or using preheating modes more frequently can significantly reduce shaking.

[DiPreston]

Having driven for many years, I find the shaking issue during cold starts in winter quite troublesome. Insufficient engine lubrication at low temperatures, thickened engine oil increasing internal friction, unstable spark plug ignition causing combustion imbalance, all lead to body sway. Weakened battery with slow discharge, plus air sensors prone to malfunction in cold weather, can also be contributing factors. Once I discovered severe carbon buildup on the spark plugs - replacing them made a noticeable difference. I recommend parking in a garage to avoid extreme cold, allowing brief engine warm-up before driving; using synthetic oil formulated for low temperatures, and annual checks on spark plugs and battery health. These measures not only improve comfort but prevent engine damage and save on repair costs. Don't underestimate these routine adjustments - they're crucial for driving safety.

[ReidFitz]

As a car owner, I've dealt with cold start shaking. The main causes are thickened engine oil at low temperatures, worn-out spark plugs failing to ignite, or a weakened battery causing unstable power supply. Poor fuel mixture in cold conditions can also lead to this. Simply changing the engine oil or spark plugs in time can effectively solve the problem with basic maintenance.