Thank you for your reply. I certain dont think I dropped a tool in there, especially since I didnt hear anything or use many tools while it was open. I did torque everything to 8.6nm. I didnt look around the chain in detail but at a glance it was alright and didnt cause any problems before. The cam gear bolts were alright and flush with the surface of the gear. My sludge was maybe a bit worse than yours but didnt cause problems before so I doubt thats it.

I forgot to mention that I changed the plugs too, ill have to check that they're properly torqued. The last thing I can think of is the furthermost spark plug gasket falling off into the valve train. Is there any way the noise could be from oil deprivation because thats what worries me the most.