Intermittent engine rattle on idle
I've recently noticed an intermittent engine rattle on idle over the last couple of weeks.
Never thought to do so earlier but I opened up the bonnet and managed to identify the source. It seems to be above the drive belt on the left side of the engine bay. I've taken a pic.
Does anyone know what it is ? There's a visible rattle to this item when it happens however when the engine is off there's no play in it whatsoever.
Thanks in advance