oil warning light has come on my s2 turbo, it runs quietly, no ratlles, smoke etc, changed the pressure switch but no joy, i've put a pressure gauge on and it has about 7psi on idle, and just over 1 bar at 2000rpm, the car has had a new oil pump fitted when the engine was re built, could it be a dodgy pump or something else? pick up pipe was also changed aswell, any help greatly appreciated, cheers