Possibly a vibration type of noise, but I've tried checking the heat shields and so on, but can't find anything loose. As I say when I'm turning a slight left hand bend and the car rolls and weight is transfered it makse the noise then. And when I put it into reverse again, however when I start it in the morning, and reverse out of the drive, it doesn't do it as the revs are higher due to the auto choke.