问：汽车经常发出噪音。

检查机油水平。如果低，那将导致发动机噪音，例如滴答作用。噪音可能来自气门火车，如果可以的话，这是发动机上高英里的结果。这种特殊的型号容易在油中开发污泥，如果发动机中存在污泥，则可能导致油通道的阻塞并加速磨损。为了表明有多少磨损可以测量油压并测试气缸压缩。如果测试结果超出范围低，则可以考虑重建引擎。如果要精确地噪音，只需请求一个车辆噪声诊断。

In regard to your question about the high idle, In the majority of vehicles, engine idle speed is controlled by an idle control valve (ICV). The ICV valve can fail or a faulty or blown fuse in other electronically controlled systems can cause the IAC motor to malfunction, leading to a higher than normal engine idle speed. Failures in the ICV valve itself are often due to excessive carbon buildup in the intake manifold. Other possible causes of a high idle include vacuum leaks, a malfunctioning throttle and, rarely, a PCM/ECM malfunction. With regard to vacuum leaks, on a fuel injected engine a vacuum leak will cause a high engine idle as the engine’s oxygen sensor detect the extra oxygen entering the engine through the vacuum leak. The newly lean (too much air relative to fuel) status will result in the engine’s computer pumping in additional fuel, resulting in an abnormally high idle. A malfunctioning throttle system can cause both a high idle as well as an engine stall. A dirty air intake or cracked air intake tube is often the culprit. If you desire that this high idle problem, as well as the near stalls that you have described, be diagnosed by a certified Mechanic, dispatched by万博体育入口到您的位置的权利，请要求engine idle speed diagnostic - high idleand the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact万博体育入口as we are always here to help you.