dom it could be the manifold heatshield as the ally cracks and loosens the bolts so it does rattle a lot on tickover.
Yeah, i'm swaying towards that at the moment, I'll have a proper nosey at the weekend when I have some daylight. If it is the heatshield, is there any way of sorting it? I used jubilee clips on the cat heatshield but the manifold one is a lot harder to access

Is it blowing if not then as Len said you could have loosened the heatshield
Initially I though so, but now i'm not too sure. I may have just been thinking the worst, a couple of others have listened to it and said that they don't think it's blowing. As above I'll have a really good poke around at the weekend, hopefully it'll just be the heatshield
