Hello. I have a problem with my E90 330i. One of the expansion plugs that inside of intake camshaft came out and drill a hove in valve cover. does anybody know what is the main purpose of plugs in camshafts. Camshafts are hollow on N52 engines that reduces its weight. I am guessing that plugs prevent oil getting inside cams. I am planning on removing those plugs so I dont have this issue in a future. Any ideas?