Im thinking about buying this car but was wondering if anyone would have an idea what could be causing this noise. It is a loud clacking sound, im thinking it could be vanos or a cam. The sound is coming from the front driver side of the motor under the valve cover. It had a used high pressure vanos pump installed into it a few years ago. The car has been sitting for 2 years now due to this issue. The guy that owns the car said it was running fine then the car went into limp mode when the noise started. It threw a Vanos code and showed the half engine light. I screwed up when i went to check the car today and didnt bring my code reader. I have a video of the sound but i cant seem to add it to the post. If someone could tell me what format i need to convert it to that would be great. The car is a 2007 e60 M5 with 106k miles on it.