Why Does the Car Idle High When Cold Starting?
2 Answers
High idle speed during cold start is a normal phenomenon. More information about high idle speed during cold start is as follows: 1. The purpose of high idle speed during cold start is to allow the car to reach normal operating temperature as quickly as possible. After the engine warms up, the idle speed will return to normal values. 2. Engine wear is more severe at low temperatures compared to normal operating temperatures. Additionally, gasoline atomization is less complete at low temperatures, resulting in slightly poorer combustion conditions in the cylinders. 3. Generally, the lower the ambient temperature, the longer the high idle speed will persist. The normal idle speed after the engine warms up is typically around 800~900 RPM.
Having driven for over a decade, I've noticed that high RPM during cold starts is quite common. When the weather is cold, the car needs to warm up quickly, and the engine requires extra fuel injection to raise the temperature and lubricate the components. After waiting three to five minutes, the RPM gradually drops. If this happens frequently, it's worth checking for carbon buildup in the throttle body or whether the idle control valve is stuck. If these parts are dirty, the control system may incorrectly adjust the RPM. Last time, I disassembled and cleaned them myself, and it improved significantly. Otherwise, fuel consumption would spike, affecting the wallet. Safety-wise, it's not a major issue, but the loud noise during startup can be annoying. I recommend regular engine maintenance and not skipping it.
