Scan the OBD2 terminal for the computer to check for any trouble codes stored there.
Many parts on top of the engine can go bad & access is difficult unless the engine is out.
Probably will need to replace the oil filler tube, power steering vent hose is too short & it usually dumps fluid on the engine opposite side of the AOS. The cam chain tensioner underneath the A/C compressor should be removed & tested to insure you can pump it up like a hydraulic lifter or replaced with new one. When removing engine just unbolt A/C compressor without disconnecting hoses to prevent loosing charge. Possibly most important is while cam covers are off replace the cam chain wear pads found here:
Pelican Parts - Product Information: 996-105-253-00-M100
This requires removing the cams properly to prevent damage, see the tech articles section for DIY info & pic's.