If it aint rattling and everything is quiet, leave well alone. I have a 51 plate 2.2 vectra estate with 37000 miles on the clock, i drop the oil and change filter as the oil just starts to go off colour as i dont pile on the miles this could be every 6 months or so. I will seek Benny when the time comes for change, but my advise would be buy genuine parts all of the time, you pay extra but you get quality and some come back if the item fails :thumbup: