BMW N62 V8 Oil Usage – Burning, 545i, 550i, 645csi, 650i, 745i, 745li, 750i, 750li, X5, X6
This answer is applicable for many BMWs in addition to the one listed below.
I seem to be using a lot of oil. I am using about a quart every 1000 miles which is far more than it used to be.
Typically, when a late model BMW engine starts to use more oil than has been “normal”, this can be traced to a problem with the crankcase ventilation system. On the N62 V8 models (such as in your 545i), the pressure regulating valves can clog or rupture. The valves are located on the right and left valve covers, under the plastic trim covers. The valves are not expensive, you may want to replace them and see if this cures the oil usage.