hello everyone! i have a problem and would like some advice on my 2000 x5 4.4 sport it sounds like a garbage truck when it crushes, when i start it. the truck was fine when i parked it monday night and i didn't turn it on until wednesday night and when i did the crunching started. it is on the passengers side. about a week ago i replaced the seals on the vvt's because they were slightly leaking after that all was fine leaking stopped. service engine soon light came on i plugged my scanner on the car and it gave me code of OF then 21 which is camshaft vanos control cyl#1-4, i was told by a friend to clear the code and drive it so that the oil pressure can rise again because it had lost the oil pessure and that if that didnt work it was a big problem. and then i read that this is a common problem and could be a loose or bad wire/sensor? i cleared the codes 2 x im not sure what to do nor check for at this point i am very handy but not enough to go into the engine. its an old truck with over 100k she looks and ran great prior to this and still does just sounds really bad.