Bessie,
I had a noise which sounded like a wire was tapping on a metal part. The noise comes and goes unpredictably, so it was hard to catch.
You wont believe this - I finally traced it to a knackered engine mount! The engine mount was completely deflated, lowering the engine to one side, which when I corner, or go over uneven road which lowers the car to one side, causes the lowered engine to rub against some other part in the engine bay.
Hence the occassional 'crick crick' noise.
Let me know if your case if similar - may i suggest u check ur engine mount?