A few weks ago I was getting a tapping noise at start up. Took her in (with 8000 mi on the clock) and the folks at my BMW dealers had it back in less than an hour. The rep said it required an air bleed. Saying that air gets in there an sometimes needs to be bled. Now the noise is back. Anyone ever hear of this condition. I guess I'm still thinking when a valve is noisy it's bent, or the oil is low. or insufficent oil pressure. Is this going to be a problem that appears from time to time? Is my BMW dealer blowing smoke Up my BVD's?