MINI Coupé R58 (12/2010 - 05/2015). MINI Cabrio R57 LCI (04/2009 - 06/2015). MINI Clubman R55 LCI (05/2009 - 06/2014). MINI R56 LCI (05/2009 - 11/2013). The PCV diaphragm cap is subjected to constant negative pressure, as a result, any cracks or leaks in the rubber seal will cause engine malfunctions.