I recently purchased a 2005 Z4 with a 2.5 motor and in looking in the oil fill opening and seeing some other questionable things, I'm beginning to think that the engine has not had much loving care in the form of oil changes. I happen to be an Amsoil dealer and will be changing it over soon but before that am thinking about flushing it a couple times in quick succession with engine flush. Anyone have any experience or thoughts on running a flush through this engine? Thanks!
