Is it normal for the engine to run at high RPM when just started?

[JosephineLee]

It is normal for the engine to run at high RPM when started. The car needs high RPM to allow the engine to quickly reach normal operating conditions, requiring a richer air-fuel mixture, increased air intake, and fuel injection, resulting in higher RPM. Cold weather lowers the water temperature, causing the engine idle speed to increase. Depending on the water temperature, the cold engine idle speed will gradually decrease from over 1200 RPM until the engine reaches the normal operating temperature, stabilizing at the standard idle speed of around 800 RPM. High RPM is generally caused by excessive carbon deposits, and timely cleaning of the throttle valve can resolve the issue. Other reasons for high engine idle speed include: 1. Idle switch not closing; 2. Faulty idle control valve; 3. Air intake pipe leakage; 4. Incorrect valve timing; 5. Fuel injector dripping or clogging; 6. Exhaust system blockage; 7. EGR valve opening during idle conditions.