When I'm off the gas there is a faint chattering (like when you put your tongue to the roof of you mouth and make a noise). This only happens when the car is upto working temp and not on gas. A chap from the garage had a look and could not see anything and put it down to a heat shield, which it can't be if it goes away when my foot is on the accelerator. Can anyone help?

 

Could be the cat in the uppipe rattling, depending on your car. Comman problem on the newage. Simply decat replacement solves it and saves your turbo.

 

Thanks, I did forget to mention the noise goes away when I depress the clutch. Could this still be a cat, as it sounds like its from the front wheel?