It most likely just needs new chain ramps. These are plasticky pads that the chains run on and are activated by aforementioned adjusting mechanism. The pads are quite cheap but the labour cost is high which is why I did mine myself. A great learning experience! Search this forum for cam deviation and you will find your answers.
Oh, and welcome to the forum!
__________________
James now has: 2008 987S 6 speed
Crashed: 2010 987.2 pdk in speed yellow!
Sold to a cool racer chick: 2004 986 S
YouTube channel: the PORSCHE as seen by NewArt
www.youtube.com/channel/UCohdrH2xHTklM1thxk0KKOQ?