I have a 1994 530ia, with my engine replaced at 72,000 miles. The problem was the interaction of sulphur in US gasoline with the nickel coating of the original engine block. After awhile, the coating becomes "etched" and will not hold compression. The the replacement blocks do not have the nickel plating and do not have this problem. This was the only major problem I know of with the E34 V8's. They did tend to leak power steering fluid at some of the hose connections, which can be repaired. Also, as with all E34's, the front end control arm bushings tend to wear out at 80 to 100k miles, causing a shimmy problem. The automatic transmission fluid should have been changed at 30k intervals - these transmissions seem to be finicky about being serviced. All in all, these cars are well designed and built and are fun to drive and should last many years with proper maintenence.