Why does the car jerk when starting cold?
3 Answers
Cold start jerking can be caused by: 1. Engine carbon deposits: When carbon builds up in the engine, it not only reduces power and increases fuel consumption but also causes unstable idling, leading to jerking during cold starts; 2. Faulty spark plugs: If the ignition efficiency of spark plugs decreases, the combustion conditions in each cylinder will vary significantly, resulting in engine vibration accompanied by jerking; 3. Insufficient engine warm-up or lack of maintenance. The transmission fluid should be replaced every 50,000 kilometers. If the transmission fluid contains excessive impurities, the jerking sensation will be more pronounced, and the shifting speed will also be significantly affected.
Last winter, when I started my car in the cold, it kept jerking, which made me quite nervous. I felt it was because the car had been parked overnight, the engine was too cold, and the fuel wasn't burning completely, as if the gasoline sprayed into the cylinder didn't disperse properly. Later, I talked to a mechanic, and he said that issues like a dirty throttle or carbon buildup could cause this, obstructing airflow and leading to unstable starts. If this problem occurs frequently, it might damage the engine and increase fuel consumption, so I've developed the habit of warming up the car for a minute or two before driving off slowly. Sometimes, worn-out spark plugs can also be a reason—I once replaced a pair, and it improved significantly. Remember to be extra careful in cold weather and avoid stomping on the accelerator suddenly to prevent accidents.
My old car always jerks when starting cold, which is quite annoying. As an ordinary car owner, I think it's likely related to internal components, such as worn-out spark plugs causing weak ignition, or clogged fuel lines making gasoline flow poorly when cold, leading to erratic power. Another common issue is a stuck idle control valve, causing the engine to misfire during cold starts. Every time it happens, I check if the air filter is clogged, as insufficient air intake can also cause trouble. If it keeps shaking persistently, it's advisable to seek professional help for system cleaning sooner rather than later—unlike my last time when I delayed repairs for months, resulting in increased fuel consumption. Overall, prevention is easier than repair, and regular maintenance saves hassle.
