Why does the car shake when starting cold in winter but returns to normal after a while?
1 Answers
Winter cold start shaking that returns to normal after a while is caused by: 1. Low ignition energy: When the engine temperature is too low, both fuel and lubricant temperatures drop significantly. Cold starts require richer air-fuel mixture, which in turn demands higher ignition energy. Excessive spark plug gap can reduce ignition energy, causing engine shaking; 2. Incorrect air-fuel mixture ratio; 3. Uneven cylinder performance leading to engine vibration. Warming up is the first and most crucial step for winter driving. Due to low temperatures, lubricants become much more viscous than in other seasons and flow poorly. Warming up doesn't require waiting until the engine reaches optimal temperature - you can start driving once the temperature gauge needle begins to rise.