Why does the BMW 5 Series fan make a loud noise at high speed?

[LaLuna]

BMW 5 Series fan makes abnormal noise at high speed due to high engine temperature and poor fan cooling. The following is a related introduction about the BMW 5 Series: 1. Model introduction: The BMW 5 Series is the most advanced luxury sedan produced in China so far. The new 5 Series is 66 mm longer than the previous generation. The power system of the BMW 5 Series has been further enhanced. The top version 545i is equipped with a V8 engine from the 7 Series. 2. Vehicle features: Rear seat entertainment audio-visual system. The rear seat entertainment audio-visual equipment is equipped with two 8-inch color screens on the back of the front seats, including a rear central console, an integrated DVD player, a DVD storage box, and a remote control. At the same time, an infrared interface and wireless headphones are provided. The rear seat area temperature can also be individually adjusted for a comfortable journey.