First off my car is a 2002 Z28 I bought my car last year new, and when the odo hit 3k miles, I switched to synthetic after some reading and asking around. People said everything would have seated by this time. So everything's good, it comes to about 5k miles and I feel I should change the oil. I'm real busy with fulltime work and fulltime school at the university, so I have to take it to the dealer. I go to pick it up and I notice they put regular mobil non-synthetic in it. DOH. Well, Im driving it around and I notice it has what seems to be a loud lifter tick? I figure its just gonig to go away, but it never does. So about a month later I change the oil back to mobil 1 syn. I notice some light metal shavings stuck to the drain plug magnet. WTF MATE. And I go to start up the car and there's still a tick. As of now, the car has about 10k miles on it. My question is, do you think that the switch from synthetic to nonsynthetic caused this? I talked to the dealer and they said there's nothing they can do about it. What should I go about doing next?