Engine Cooling System problems of the 1998 BMW 740

Low coolant message came on while driving. Within a few miles, radiator cap overpresured and steam burst out while on the highway. Pulled over and was towed to the dealer. Replaced coolant hoses. 4 months later, low coolant message came on again while traveling; stopped at a service station to check level; level was very low, and a slow leak was visible. Replaced coolant reservoir assembly. 6 mos later, check engine light came on. Dealer replaced sensor. One week later, the low coolant message came on again (3rd time). Coolant was low; took to dealer for repair. All work was at owner's expense (non-warranty).

While driving on a higway and taking a turn over a curved portion of the highway I found the power in the steering was not functioning and the steering wheel became extremely hard. Whe I tried to brake and pull to the side the brake was also quite hard. The car had then to be towed to a BMW dealershi, and the problem was detected and fixed. I was informed that the water pump had failed which resulted in the belts to break, causing a loss of power in the steering and the brakes. This was quite a disturbing experience whiel driving this car on a higway and could have caused a major accident. The BMW 740 IL is quite a heavy car and without power in the steering and the brakes it is very difficult to control the car at highway speeds. The power system failing due to water pump failure appears to be of serious concern in a vehicle that is advertised as one of the marvels of engineering. The car is still under warranty.