Taz_devil

I am in the process of getting the car sorted as best I can. I've had a strange noise now for a while, but I let it go as I was also getting my downpipe leak fixed. I thought perhaps it was the exhaust or the heat shield. The leak is fixed, plus new turbo has been put in. The noise is still there and more frequent now. The heat shield is off completely (long story) so it can't be that or the exhaust I figure.

The sound appears to come from the top of the engine, from the intercooler, when sitting in the cabin. I have never managed to get out and open the bonnet fast enough to pin point it before it stops. It occurred the first time after a 4 hour drive, and has done it ever since on short or long trips. It only lasts a while, rattles for a second, stops, then rattles again. It does this for a few seconds then disappears. Blipping the throttle also makes it stop, though it can return once the revs fall. I'm wondering if it could be the cat in the uppipe being lose, but as I said, it appears to come from the top and center of the engine. I really have no idea to be honest. Any ideas on what this could be?

edit: further info that may help. I do have a wearing clutch, its not too bad and hasn't caused an issue so far. Could it perhaps be a clutch related noise? The rattle occurs in neutral with the clutch out, as I have a habit of parking the car that way. I really wish I could be more descriptive other to say 'its a rattle'. It sounds like something scraping the intercooler, or someone playing a washboard with no particular rhythm