I recently started to hear a strange sound like a 'chattering/rattling' sound from under the engine. I traced the noise to the airbox initially when I removed the top rectangular intake section. Having removed the filter and taken off the intake hose leading to the turbo the sound seems to be coming from the intake hose. Does anyone have some advice as to what this could be. Could the exhaust cause noise to travel up the intake system or is something mechanical on the way out?? Thanks in advance of any help/advice.