Cold car idling, dangling, hot car is better. It's not that the spark plug is broken.

This spark plug is not necessarily broken. It is common for cars to shake at low speed and idle speed. Because the engine jitter is the worst when idling, if it is sudden jitter, you can consider readjusting the engine fixing bolts first. Secondly, the common causes are dirty throttle body, atomization of injector or poor ignition of spark plug. Check whether the ECU has an error code, and whether the corresponding water temperature sensor and throttle opening sensor work normally. Shaking with cold idling. Hot car may not be the spark plug is broken: 1. The most common problem is that the throttle valve is dirty or invalid, which will affect the idle jitter. The key reason of dirty throttle is that there is carbon deposit at the joint between throttle valve plate shaft and throttle body, which affects the inaccurate throttle opening. Naturally, idling will tremble and shake; Of course, we can clean the throttle valve first. If it doesn't shake after cleaning, the throttle valve is dirty. If it still shakes after cleaning, it may be that the throttle assembly is damaged and the throttle needs to be replaced. I remind you that since most vehicles use electronic throttle now, it is natural to learn to idle after cleaning the throttle.