The engine sound is wrong after the new Passat has a new throttle.

The oil does not meet the standard or is added too much.

Causes and solutions of loud throttle noise: the throttle is too dirty or damaged. It is recommended to clean up the carbon deposit on the throttle or replace the throttle. The throttle of an automobile is generally at the engine air intake, behind the engine air filter and in front of the intake manifold. The main function of the throttle valve is to control the air intake, which will affect the fuel injection. As the air intake increases, the fuel injection will also increase.

After the vehicle is used for a period of time, the throttle and nozzle will become dirty. If the throttle and throttle are too dirty, there will be phenomena such as weak acceleration, loud noise, high fuel consumption and car shake, which need to be cleaned regularly. However, it does not mean that the more frequently the throttle and nozzle are cleaned, the better.