Why is it difficult to start the engine in cold winter weather?
3 Answers
The reasons why it is difficult to start the engine in cold winter weather are: 1. Intake system: As the weather gets colder, the atomization effect of fuel injected into the intake pipe becomes poor. If there is carbon buildup in the engine's intake system at this time, it will make the air-fuel mixture difficult to ignite in the cylinder; 2. Fuel supply system: It is difficult to establish fuel pressure in the engine's fuel supply pipe. When the temperature is extremely low, water and impurities in the fuel mix together, causing fuel line blockages, resulting in difficulty starting or failure to start; 3. Ignition system: In cold weather, if the ignition capability is too weak, it is difficult to ignite the poorly atomized air-fuel mixture. At this time, it is necessary to check whether the spark plugs are aged, have excessive gaps, or if the ignition coils are aged.
In winter, engines are hard to start in cold weather, which is a key point I've summarized from years of driving experience. The main reason is that the cold makes the engine oil thick and sticky, like a viscous sauce, making it difficult for the internal parts of the engine to move, and the starter needs more horsepower to turn. The battery performs poorly in low temperatures because the chemical reactions inside slow down, significantly reducing power output, leading to weak ignition when the charge is insufficient. Additionally, fuel doesn't evaporate easily in cold temperatures, affecting the formation of the air-fuel mixture, making the engine harder to ignite, which is especially common in older cars. Plus, changes in air density reduce intake efficiency, and the ignition system may become unstable. I remember one year when it was minus ten degrees, my car wouldn't start at all, and it was only after switching to winter-specific oil and a new battery that the problem was solved. It's recommended to check battery health and switch to low-viscosity oil before the cold sets in, park in a sheltered garage if possible, and turn on the headlights for a few dozen seconds to warm up before starting—these small habits can make starting much smoother.
As an automotive enthusiast, I fully understand the underlying causes of difficult cold starts: low temperatures cause battery performance to plummet due to reduced electrochemical reaction rates, resulting in insufficient current output. Simultaneously, engine oil viscosity increases dramatically, creating greater rotational resistance in the engine. Fuel is less volatile in cold weather, leading to improper air-fuel mixture ratios that affect ignition efficiency. I've also observed that cold air's higher density alters engine intake characteristics, potentially causing delayed or weakened spark plug ignition. From experience, using synthetic oil to reduce viscosity, installing battery preheaters, and regular ignition system cleaning can significantly improve starting performance. Living in northern regions, I've developed the habit of covering the engine compartment for insulation when parked and avoiding direct starts in extreme cold. Additionally, fuel filter clogging can also cause issues, requiring systematic inspection of these components.
