Variocam Issue?

[freserf]

The previous owner of my 1997 Porsche Boxster listed the following problem for the engine. "Valve train noise at high rpm. Possible variocam solenoid bad. No issue at low rpm." The following codes showed up when I revved the engine or were already set when I hooked up my reader. P0300, P0301, P0302, P0303, P0341, P1319, P1313, P1314, and P1315. I did experience the misfires without driving the vehicle and I understand what they mean ... trouble with bank 1 misfire and possible camshaft sensor issues. The emission codes are just warnings because of the misfires. Stop driving to prevent damage. So far I have checked and confirmed good camshaft sensor and compared both variocam solenoids at about 12.7ohms with good voltage to both. I can also hear them clicking when testing with my power supply. Having worked with many types of solenoids, I know they can test fine, but not really work well as they age. The car has 86000 miles and the documented history is not the best. I have also read through many posts from various sites related to this similar issue and still do not have an "Aha", idea to run with. Spark plugs were extremely worn and coils looked good ... and there was no signs of broken plastic parts or metal in the oil or filter.

I am leaning towards timing chain wear or more likely tensioner pad wear even though I haven't seen evidence so far. I want to pull bank 1 side head cover and visually check the tensioner pads. Do I need the special P253 tool or just something to hold the ends of the camshafts in place in order to pull the cover. I don't mind being a perfectionist, but the KISS method works best for me.

Lastly, there is a loud rattle for about 1 second on start up and read this may be normal and using a different grade oil may reduce this ...

Is it possible due to failing IMS since it is driving bank 1 to cause these symptoms?

Just want some input from those who have experienced similar situation. Thanks for any input and have a great day.