I have a mk4 astra with a z20let. it is burnining excessive amounts of oil.....as in one litre a week (250 miles)!!! it had a vxr turbo fitted 20,000 miles ago. if i leave engine idling for a min or so, and "blip" the accelerator i get blue smoke from the exhaust, but nothing at all when starting, driving or hard acceleration etc. i found a flat and split breather pipe under the crossover pipe witch i replaced. this improved the smoke when idling but has not affected the oil consumption. any help on this would be much appreciated.