Why is it difficult to start a car in cold weather?
2 Answers
Difficulty in cold starting may be due to a faulty fuel pressure regulator or excessively low coolant temperature. Here are some solutions for cold start difficulties: 1. Low engine temperature: The temperature inside the engine is insufficient, and both the fuel and lubricating oil are not warm enough. Therefore, more fuel should be injected during cold starts to meet power requirements. Poor fuel atomization at low temperatures leads to reduced ignition energy, affecting performance and causing the car to shake. Aging ignition coils, spark plug high-voltage wires, or electrical leakage can also reduce ignition energy. 2. Excessive carbon deposits on valves and intake passages: Carbon deposits can absorb a certain amount of fuel, causing the ECU to make incorrect judgments. For example, if the computer controls the injection of 100 units of fuel-air mixture, but only 90 units actually enter the cylinder (10 units are absorbed by carbon deposits), even if the remaining 90 units burn completely, the required power performance will not be achieved, and shaking is inevitable.
I've got plenty of experience with this! The most common cause of cold start difficulty is when the engine oil turns into a paste-like consistency, especially in older cars using high-viscosity oil. Last winter, my old Passat had this exact issue—it sounded like it was wheezing when starting. Battery problems are another culprit; at low temperatures, the charge can drop by a third, and if the starting current can't keep up, it's game over. Clogged injectors with carbon buildup can cause poor fuel atomization, like a showerhead that's blocked. Low fuel pump pressure, worn spark plug gaps, or a frozen PCV valve can all affect ignition, making the engine struggle to breathe. The trickiest issue is the fuel evaporation system—leaky hoses or a stuck charcoal canister purge valve can mess up the air-fuel mixture. My advice: switch to 0W-grade oil before winter, and don't hesitate to replace the battery if needed.
