Thanks for your detailed answer, and being an Electrical Engineer, I appreciate the difficulty in diagnosing something over the net without having it with you.
I too had the assumption about the oil filter, so not having another to hand, removed it for 10 mins to see if this was causing any problems or any blockages, didnt change anything.
I keep asking about the voltage to the VVT GEAR SERVOMOTOR/ACUTATOR, as this is right near the spark plugs that I changed, I also know this controls the cam or valve movement, so wondered what voltage I should be getting to this ?.
I also ask, as when I remove the plug from it I get no extra fault codes, so wondered if this was the fault 27bb cam control outlet-vanos, that keeps coming up on INPA software.
Would it do any damage to remove the oil filter tempoarily, as its brand new oil in the system.
Also forgot to mention that the plastic end of the dip stick is missing, so is hard to check the oil level.
However when doing oil change, sure I read 4.55 litres max, which is what I put in, 5w/30 fully synthetic. I have no low oil level light illuminated, and I have no oil pressure fault codes, does this still mean there could be an oil circulation problem ?.
Where is the oil pump on these, and are they belt driven or electric.
I hope im not the only one who asks one million questions, but you are coming up with the same things I am, but not being a qualified mechanic, and never worked with these vanos units before need to ask a lot of questions to narrow down the problem. Also sprayed eccentric shaft sencor with contact cleaner when servicing
?. When I remove this plug now it does give me fault codes 2852 VVT REF SENSOR and 2850 VVT GUIDING SENCOR, which make no difference to the engine when the car is running, and also the codes do not re-occur when plugged back in, which tells me that this is not the problem either ?.