The "knock" almost makes the car sound a little bit like a diesel engine.

One other thing I noticed was I had to drive the car in reverse for about 100 yards. After about fifty yards, I noticed a considerable leak of oil on the pavement. I say considerable as it left quite a trail in the parking lot at my work and then leaked for a while after the car sat for a couple of hours.

For certain I have a leak at the valve cover as the seam between the head and the valve cover has a significant build up of oil. When the car is running, the heat from the engine burn the leaking oil and creates quite a bit of smoke.