Engine noise

[Marcus1991]

I replaced my Aux tensioner and belt last week, all was well until this morning. Not all the time but most of the time I hear a noise comming from the engine, almost like keys jingling around. When i was driving through the town is made a louder jingling noise and then stopped (just like when a belt is squeaking from being loose and the stops) and after a few minuets the jingling noise reapears. Bit of a long shot, but does anyone know what it could be? Thanks