What's this noise?

[oAllElseFailo]

There's some clunking noise coming from inside the engine bay, I don't know if its internal or external.. then again I don't know what it is period.

There's no loss of power in the car and it drives fine even after accelerating and letting it coast the noise lessens but when the car slows down the noise hightens again and when it idles it slowly drops its RPMs until it dies, ontop of that there's a hole in the radiator hose which i don't know would cause a problem of this clunking but would anyone have an idea of what it may be? It's a 1999 996 with 65958 miles on it. Thanks.