Is an idle speed of 600 to 700 RPM normal?

[McDiana]

This depends on the engine displacement. If the displacement is above 2.5L, an idle speed of 600-700 RPM is normal. If the displacement is below 2.0L, the idle speed should be around 800-900 RPM. Normal engine idle speed values: Generally, the normal idle speed for most vehicles does not exceed 1000 RPM, typically ranging between 600-900 RPM. However, during cold starts, the idle speed will be higher because operating the engine at low temperatures can cause wear. To prevent this, the engine control unit (ECU) will increase the idle speed to quickly reach the engine's optimal operating temperature. Once the coolant temperature stabilizes, the idle speed will drop back to the normal range. Abnormal idle speed (too high or too low) may indicate a fault: The idle speed is preset at the factory and should not vary significantly during normal use. If the idle speed remains too high or too low after the engine has warmed up, it may indicate issues such as an intake air leak, faulty fuel injectors, or other problems that require inspection at a repair shop. If the idle speed fluctuates and the vehicle shakes severely, it is likely caused by excessive carbon buildup in the engine.

[LeJeffrey]

As a daily commuter, I drive an economy car that usually idles between 600 to 700 RPM. Initially, I thought this might be too low and could cause issues, but over time I realized it's quite normal, especially after the engine warms up. Modern cars are designed for fuel efficiency, with lower idle speeds to save fuel and reduce emissions. If the RPM drops below 500, you might feel engine shaking or instability, but around 600 it runs smoothly. On cold starts, the RPM is higher initially before settling into this range. Occasionally, it might rise slightly with the AC on or when on an incline, but generally remains normal. In short, don't worry too much as long as the car runs smoothly without strange noises. Just remember to perform regular maintenance checks to ensure sensors and other components are working properly.