Mathew & ERM324, I had the exact same noise from my engine. 2 months go by, car in the shop. BMW was very slow. BMW regional rep. got involved. Finally pulled the motor, main bearings worn badly, rod bearings great shape, 14k on motor. Just as I thought, worn bearings, I just knew it! Told you BMW. I took more photo's than a Kodak store. New crankshaft, main and rod bearings replaced, $14,800.00 later, (covered, no cost to me)...........we start the engine, same sound. Hmmm, was it the bearings? Don't really know, BMW gives up and orders a new engine from Germany, 1 more month goes by, $27,400.00 later (covered, no cost to me), over $34,700.00 total on the last repair, no more ticking. I'm happy but confused.
. BMW never could explain it to me. It's now been one year, 6k on new motor, no issues. This M3 is my first BMW ever, I really like this car, but now I listen to every M3 I see. I wish you good luck, that ticking just drove me nuts! BMW took care of me, I hope they take care you guys!