Audi Oil pressure problems in need of specialist near birmingham

[Jja95]

Hi i have an 2011 audi TT 2.0tsi cesa engine ea888 gen 2.that has a low oil pressure light, i need somebody very knowledgeable on the 'Oil pressure light' problem as this is a tricky one, please have a read of the problems im having with my car if u can, any ideas on where to go near west mids bham/where to check on the car etc will be appreciated


The car mechanically has 0 psi oil pressure at idle hot or cold on a test gauge but oil pressure light illuminates before starting vehicle key in on position. When running the mechanical gauge flicks up in pressure as soon as i rev the car past idle but its still below recommended (approx 12 psi at2k rpm )but it sounds fine and drives fine until EPC light kicks in and puts it into limp mode( unplugged the sensors to stop the oil alarm going nuts) . Ive tried replacing the Oil pump with x3 different units, a few different oil filters, tried new complete oil filter housing, ive changed the pick up, n428 valve, my mechanic also rebuilt the balancing shafts as we found on the internet they can get blocked and restrict oil flow apparently with no success, he changed timing chain and tensioner as it was rattling slightly on start up and it still is rattling and also tried oil anti drain valve in the head while we where there, the car has also done about 5 thousand miles with the oil pressure light and apparent low oil pressure and seems fine which is very confusing i just want the cars full power back and rid of this light the car also is only 32k genuine miles, and also the oil pressure light illuminates with keys on before vehicle started which makes me think im oil pressure testing it wrong and it could be electrical im no mechanic but my mechanic friends are all stumped and say who knows. shall i take it to audi?
if so does anybody know which one will be best for these problems
Thanks for reading .
ive probably also tried other parts on the vehicle but i cant remember at the minute.
This is also my first post on a forum so apolagies if any mistakes thanks