Oh yeah ,I remember now ,these had a problem with the vacuum pump arm ,unreliable .Mine had weak braking and no shut down due to the pump .Pulled the vac pump and found it had hand grenaded.In further study and research of the pumps demize I learned of its issues ,the arm piece on the pump that rolls up and down a turning piece off the crank (like a roller coaster) .That arm broke sending metal further down into the block gallery.Its a bit of a mystery were all the metal went but its safe to say I would start here.I fixed it with a vac pump off a 2.5 88 190d ,matched up and was better built.Had power brakes and correct shut down .This is probably why the car was so cheap ,but a very good motor .Clean out the pan if this does end up being the problem with the noise ,its the metal on metal of the pump and its pieces still riding on that roller piece.