Engine warning light (yellow) lit up, with primary code 2d60, which repair shop said indicated camshaft exhaust stuck (secondary code 2c58 - boost pressure blocked). Repair shop checked oil and vanos filter for debris, but found none. Reset computer and light did not re-appear even after 4 mile test drove. I subsequently drove car 30 miles, and no problems (never felt anything wrong actually even with engine warning light on). Repair shop indicated potential timing chain issue in future, but could do nothing more at present time. Mini dealer (not place of repair) indicated over fill of oil could have produced warning light. Two months prior I had oil change at different repair shop (needed rear brakes) and hadn't realized they had overfilled oil. Anyone had siimilar warning light issue and/or oil overfill problem?