where do i start a thread and how? i need help with my astra 1.6.16v sxi, problem is when driving and moving off in first gear, and moving up to second the car suddenly judders and the revs drop but only for a split second, any help would be great. oil, filter, air filter, spark plugs changed, and the throttle body cleaned. this is driving me maaaaaaaaad, It does not do this every day, only a few times a week but enough to make the want to get rid of it. it's an 03 reg. Any help please.