1994 318is - m42 motor

please watch the video if you have a minute.. The engine sound has lowered since I changed the oil but is DEF still there. What are your speculations?

http://www.youtube.com/watch?v=7MEFf5H98-4

The sound quality ist the greatest, but... Seems to be quite a bit of valve clatter from the engine bay (sticky lifters or worn chain?) and it sounds like there's a misfire from the part recorded at the rear of the car.

I agree on both. Could it be excess cam wear and clearances? Just my $.02, I'm still used to pushrod motors.

The clatter in the front sounds like a bad timing chain tensioner. The exhaust note sounds like there's a hole in the exhaust system somewhere, probably the muffler.

Timing chain tensioner on the M42 has been notorious for giving up. Grab a long flat bladed screw driver, put the butt next to your ear, start the car, place the blade of the screwdriver against the timing chain cover and have a listen (if you have a proper stethescope, it would be all the better).

If you hear nothing from the case, move over to the valve cover and have a listen. Report back your results, but if it's coming from the front cover, then it's likely the tensioner.