Originally Posted by no_caffeine
Here is whats weird, it run strong. No lag, no hesitation, no loss of power.. but listen to this:
Someone said it maybe the valves, I legit haven't had time to check them- went on vacation to DC and now I'm swamped with trial cases. Any other thoughts besides valves?
Sounds more like sticky lifters to me.
If you were off a tooth it would idle and run very rough.
If it's got hydraulic lifters, over time they'll get clogged up with **** and loud.
You could try pulling them out and soaking them in diesel or kerosene overnight and trying to manually move the internals around a bit and then put them back in to see if that fixes them. Shouldn't be too difficult a job and it doesn't cost anything to do besides replacing the valve cover gasket and buying the diesel/kerosene.
Though I don't know BMWs very well so someone else might have a better suggestion.