Hello, my car/engine have very strange metallic rattle ,
Engine 1.8T BFB same as AMB or AVJ or BEX, year 2003
I changed cam chain tensioner and cam chain , measured oil pressure is 1.3-1.4 / 19-20psi at hot idle... cleaned oil sump and oil pickup... NO CHANGES at all...

noise come in when engine is hot and idle, when I rev it past 1000rpm noise go away....

here is a video... please help

1.8tbfb - YouTube

(sry for bad english)

 

I am fairly sure it's your cam tensioner making that noise.

 

I thought the same way, but as I said I changed tensioner but.... I find out that this noise is coming from failed catalytic converter... the content of cat is loose and rattling inside...