Liqui Moly 1009 hydraulic lifters additive, 300 ml (Automotive)
When VW Lupo 1l BJ 99 my daughter 120Tkm, mostly short-range 5-15 Km highway, the valves began significantly to rattle like old sewing machines sound so. Also saw residues / light brown streaks on the oil filler neck. So daring experiment and after 5