thanks sa replies chieffy and fundy.

im not sure kung valve cover gasket tawag dun.. pero yun yung cover na inalis nila nung nagpalit ako ng timing belt last year.. tinignan ko rin yung bandang ilalim, parang may leak din.. i just had it checked this afternoon.. papalitan na nga raw yung gasket, pati din daw yung gasket sa oil seal pan, paalitan din.. kasi may parang leak din dun..
2300 daw ang damage.. parang masyado yatang mahal.. mag cacanvass muna ako sa iba.. natural lang ba na magwear out yung gaskets after sometime regardless of what oil you use? nagtataka lang kasi ako ngayon lang lumabas when i switched to semi synthetic.. :roll: