One problem related to battery has been reported for the 1998 BMW 740. The most recently reported issues are listed below.
I bought this vehicle in 2002 at 96k miles it has been nothing but problems, since buying vehicle, I have had water pump failure twice, replaced radiator twice , hoses & rings. . Two battery's front bumper, catalytic convertor l. Bay, changed. . Brakes & rotors changed Nov. 11. . . . . . 3 weeks later as I was driving home from work . . I got a transmission failure. . And the car stopped in the middle of the road. . The car goes in reverse but not forward. . I have only driven this car 15 -16k miles since owning the vehicle I have had all these chronic repairs. . I'm distraught that I could have been in a serious car crash. . Not sure what to do?. . But accrd. . To many BMW owners I find on the net there is a chronic problem w/ transmission failure BMW should be held accountable. . It is dangerous and unsafe for drivers there needs to be some investigation in regards to transmission failure . .