How can i find out exactly why my car is blowing out smoke

What is your question?

When car is first started, it sounds like there is an exhaust leak. Once it warms a little it quiets down, after it warms fully and as it sits there's smoke, and when I press the accelerator a couple good times there be little clouds coming out the exhaust. After while there's a funny smell and when I drive at times there's clouds of smoke. Also at times there will be a little stutter while accelerating! I have had the PCV'S replaced and I've have used some marvel mystery oil. The oil seems to be burning faster than it should be.

What makes this problem better or worse?

I think that The longer it runs I think it smokes more

How long has your 2007 BMW 750i had this problem?

I've had the car for about a month now