I had a failing chain tensioner, which eventually failed altogether, causing the tensioner, tension rail and chain to slap fiercely; broke the tension rail, but the chain remained unscathed as far as visual inspection and cam/crank agreeing on tdc. I haven't done a compression test on this engine yet. I will be doing so after attending to the more immediate problem of getting it running again and some necessary suspension work. Do you have any info regarding your 220d as regards the shape it's in?