hey man , i had the EXACT same thing on my car. It is defin the turbo. Sounds like a rattlesnake inside the turbo everytime you let off the pedal. You need a new turbo. I am getting mine rebuilt or i might just buy a used one to replace it. Ko4 turbo is way above my expenses. =)

 

a very handy tool for this job and car doesn't need to be moving

[IMG]local://upfiles/12092/DEE883C1AA1F4CCBB73C304E16078789.jpg[/IMG]

 

Maybe it is a real rattlesnake humping your engine like this Boa

[IMG]local://upfiles/19670/BDE052FDC0C74AF8926227C7E958A4B3.jpg[/IMG]

 

i hear the sound even if i do baby the turbo, one my rpms go over 2000 and i let off the gas i hear the clicking noise. It doesnt matter if im driving or i rev the car in neutral, one it breaks 2000rpm and i let off i hear the rattle. Now its definetly coming from the turbo side and Ive been getting codes for my cat so i think its on its way out. Can the cat be making this noise. And my solution was that i bought an ATP testpipe and K04 turbo, just need to install them now and see if it changes the situation

 

that post looks familiar.. lol

 

yea man , get that ko4 installed. Its defin your turbo. I wish i had a ko4 =(