E39 Oil leak solved -- $16. and 30 minutes !!
After spending a lot of money -- $800. plus for parts only on the advice of so-called experts, discovered that my persistent oil leak was coming from the VANOS solenoid seal ($8.00 each ) on the right cylinder bank a 20 minute job.
After two weeks and the residual oil draining off, the five-year problem was solved. It was hidden by a bunch of stuff that prevented even a video camera from seeing it. What the hell I also replaced the left seal in ten minutes with a 10mm socket and wobble extension and a screwdriver for another $8.00
In the meantime the dealers and three other experts tried to convince me the valve covers that were replaced a year ago were the culprit, the valley pan gasket, the cooling accumulator, the EGR system, the backfire plate, the manifold gaskets --- yada yada ya................
The bottom line is most mechanics don't know jack.... I still belive in the value of a college education, and/ or the ability to read a manual or a Bimmerfest forum.