Is It Normal for the Engine to Rev at 1800 RPM During Cold Start?
2 Answers
Normal. More details are as follows: During cold start: The engine and the three-way catalytic converter in the exhaust header need to warm up, which requires additional fuel injection, leading to higher RPM. Cold engine: Refers to the state when the engine has cooled down. During a cold start, due to the low temperature inside the cylinders, gasoline atomization is poor. To meet the necessary combustion conditions, the electronic fuel injection system will increase the concentration of the air-fuel mixture. As a result, the engine will raise the idle speed to increase fuel injection and enhance the mixture concentration. As the cylinder temperature rises, the overly rich air-fuel mixture is no longer needed, so the idle speed gradually decreases, and the engine's fuel injection also reduces accordingly.
A cold start at 1800 RPM is completely normal. As a car owner with 20 years of driving experience, I often notice this. The engine needs to warm up quickly when cold to reach optimal operating temperature, and the car's computer automatically controls the RPM increase. It typically rises to around 1800 RPM a few seconds after starting and then drops to about 800 RPM within minutes. This is more noticeable in cold weather because the engine oil thickens, making the engine work harder. If the RPM remains high or the car shakes, it might indicate a dirty throttle body or sensor issue, so a visit to the mechanic is recommended. Don’t forget regular maintenance—changing the oil and filter can prevent problems. Additionally, high RPM during cold starts helps the catalytic converter heat up faster, reducing harmful emissions. Don’t worry about this phenomenon; as long as it drops automatically, there’s no issue.
