Is it a common problem that BYD f0 engine sounds big and small?

Your condition is abnormal. It is caused by the unstable idle speed of the engine.

Generally, the idle speed of hot cars is lower than 800 rpm, and the idle speed will shake. Vehicle idling jitter is caused by dirty throttle, intake pressure sensor or air flow meter. Just wash it.

In addition, whether the intake manifold leaks, whether the vacuum booster pump leaks, and whether the intake pressure sensor and injector leak are also matters worthy of attention. This situation can be understood by measuring the vacuum degree of the engine, and it will also lead to the phenomenon of unstable idle speed.

Have fun with the car * ask the owner. 4S shop professional technician, 10 minutes to solve.