Hey, im interested in buying a 1988 535i i found on craigslist. The guy says that the car has a very slow oil leak, which im told a oil pan gasket will most likely fix. But there is also some electrical problems with the car. The owner says that when he revs the rpm's high the car has difficulty running. Im guessing its possibly a problem with the sensors? im not sure. But some advise on fixing these problems would be great so i know what im getting into, thanks.

Oil leak can be a lot of places, the worst case would be main oil seal. The guy would tell you the easiest problem when he wants to sell the car. A pre-purchase inspection by a Bimmer specialist is the best advice I can tell you.