My Golf''s engine emits a light rattle when the engine is accelerating or under load. It stops immediately the foot is lifted off the accelerator. The noise is quite quiet, especially from the driver's side but this is probably because the passenger can pick it up being bounced back off roadside walls etc. It does not increase with road speed and remains at a fairly steady frequency as the box changes up through the gears. I have mentioned it to my dealer twice but it doesn't perform for them when I've taken it to them for a listen. The car is 11 months and 9k miles old.