Hi David, how have you and the car been? I recently replaced my pcv valve cover at bmw, unfortunately now after a month, I noticed that my car started smoking a bit when under load or hard acceleration. Almost like a dark grey colour, I am going to do some digging to see what it is, I can't see any visible oil leaks, and also oil level still max, no error codes or any lights on the dash, the car also did not lose power or so. So I am starting to think that it might be fuel related, perhaps a leaking injector. Have you noticed any smoke here and there sometimes? Perhaps it's just a high milage thing. Other than that, the car has been good!