TD4 Noise when slowing down

My 03 plate TD4 60k mileage has just developed a noise form the engine bay when slowing down ,it has nothing to do with the brakes as the noise is there when the car is being allowed to slow down without braking.. I think the noise is possibly coming from the right hand side tho i am not sure... any ideas or pointer whould be appreciated

Thanks

Noise has stopped now...thanks for all your help lol