I have used a rubber hose and it still pointed to the top of bank 2 but it is quite obvious from standing next to the car that the source is probably in this area. I will look at the top of the rod too if Im sure the noise is coming from around there. It's not something that is slightly loose, it sounds like the piston is hitting the valve really hard. But compression is excellent and there are no marks on any of the pistons, only slight carbon build-up.

Im also thinking about the valve train but can't imagine anything on the valve train would make such a loud, sharp noise. This is why I want to use the TDC as a reference signal to know the positions of all pistons and valves when the sound is recorded. The valve train also looks like it was built yesterday by angels.

I dont want to strip the engine to look for the source as I might find something, repair it, re-assemble and end up with an engine that runs 1% better but still has the noise. I would rather like to isolate it to a specific component or function and look there. Luckily modern of the shelf technology allows such tests to be done...I have also designed a bluetooth module that works with these older cars allowing music, navigation, phone calls to be handled through the Audio30 system with additional hardware in sight. Will do a seperate write-up when it has been installed. The bluetooth device will be visible as : Edmund's Mercedes.....