What is the normal idle speed?
2 Answers
Normal idle speed varies depending on the vehicle model and engine type, typically ranging between 500 to 850 RPM. During a cold start, the idle speed may momentarily reach around 1500 to 2000 RPM, but it will stabilize within the specified range once the engine coolant temperature reaches 90°C. Relevant information is as follows: 1. If the car's idle speed is too high, check for loose or leaking intake manifolds. High idle speed increases fuel consumption and can lead to more engine carbon deposits. 2. If the car's idle speed is too low, there is a safety risk of stalling while driving. Fluctuating idle speeds may indicate issues with spark plugs or ignition coils, causing the engine pistons to malfunction and resulting in severe shaking.
When it comes to what idle speed is normal, I’m used to keeping an eye on the tachometer while driving. Most of the time, my gasoline car idles at around 700 RPM, which feels quite smooth. When the air conditioning is on, it rises to 800 RPM, and that’s no issue. During a cold start in winter, if the engine hasn’t fully warmed up, the idle speed might jump to 1000 RPM, but it drops back down after a few minutes. If the idle speed is too low, say below 600 RPM, the car tends to shake or even stall. If it’s too high, like over 1000 RPM, fuel consumption increases. I once experienced unstable idle speed, and after checking, it turned out the throttle body was dirty—just a quick clean for a few dozen bucks fixed it. Paying attention to these details in daily driving can save a lot of hassle and time, especially for older cars that need regular maintenance.
