I have a brand new P68 which I have been running for about 3 weeks. It now makes this non stop clinging sound, sounds like to light pieces of metal banging into eachother. My dealer states that's normal and I should only be worried if it stops making that noise. There can be no way thats a normal sound because it has become very annoying to here. Dealer says its a flap that allows air into the unit somewhat like the top metal piece that goes up and down on a truck exhaust. Does anyone know if this is normal? it was not doing this for the first 2 weeks. Thanks in advance.