I have a knock, sounds like lifter near idle. I am 2nd owner, just bought 3 months ago. BMW service pulled and proper service from 1st owner for firsr 63,000 mi. Took car back to dealer and they replaced 1 lifter and bad oil level sensor. Knock still there, took to Ferman BMW Palm Harbor, FL, had appt for wed. 28 Jan, they never looked at car till 6 days later on 3 Feb. Their quick diag was "Needs new engine". State found fault code FC27CE, low oil and assumed it had been run dry. They never asked if we just had a bad sensor which would give that code. Now waiting on warranty adjustor, and ideas on my first BMW?