Hi my Octavia vrs mk1 has a funny sound on idle. It sounds like a metal tingly noise and it's not the tapping noise you get on the 1.8t. 

 

Anyone have any idea what it could be? 

Do you know roughly where abouts in the engine bay?  Have a listen with the bonnet up and try and work out front or rear, top end, timing side etc.

My first thought is of the tack welded heat shield on the first exhaust box coming loose.

cheers lads I'll check those yous are all great help!

The cat has a shield on top IIRC

It could be the down pipe that hits the support beam underneath, due to softened/weakened motor bushings. 

 

See this video: