PhilB

Hi all, new here. I recently replaced the rocker cover gasket, vanos motor gasket, vanos solonoid o rings and oil filter housing o ring on my 130i, has black plastic cover. Couple months on noticed oil seepage under engine cover. Removed cover and found rocker cover gasket leaking again and vanos solonoids leaking. Rocker gasket i got at SPR Parts , Frey brand, o rings from seal supplier. Any suggestions why it would leak so soon. I am a qualified mechanic