What is the cause of the water tank failure of BMW 730 heater?

The reasons for the failure of BMW 730 heater water tank are: engine cooling system failure; The heating control device is not working properly. Take BMW 7 Series 20 19 730Li luxury suit as an example. Its body dimensions are: length 5273mm, width 1902mm, height 1498mm, wheelbase 32 10mm, and fuel tank volume 78l. BMW 7 Series 20 19 730Li Luxury Suit is equipped with a 2.0T turbocharged engine, with a maximum horsepower of 265ps, a maximum power of 195kw and a maximum torque of 400nm, matching an 8-speed automatic manual transmission.