I have a 2005 Audi a4 1.8t my oil pressure light came on. Car history the car has 338000 km on it I had full synthetic in it oil change every 9 10 000 km I here Audi has sludge problems but the engine gets oil thru out it there is oil in the car and I am getting full 9 pounds of pressure my sensor has never been changed. Now the light is on everytime I shift a gear 1 2 3 4 I hear a rattling sound like a heat shield rattle type. Now I was a little late on my last oil change I went 10 000 over. Any suggestions please help.