i have the same thing on my corsa you either have to goto a garage and ask them to do it or you have to goto a motorworld and ask them what sort of oil it might be. i don't think it's the oil tho. i think it's the gear box linkage, im going to have a look on sunday at my mates garage i'll keep you posted.......
Paul ryder Cwgca@hotmail.com, February 2005