I don't know that this is necessarily an engine specific question, but maybe it is.
My car has done 22000 km. Over the past two weeks, I've noticed a rattle when I'm at low speeds and I'm accelerating. It seems to be coming from somewhere under the bonnet, but I haven't managed to localise it. It sounds to me like a tinny, metalic plate rattling.
Does this by chance sound like a particularly well known rattle? If so, I thought it might help save me some time looking for it.