i have a 1997 audi a4 1.8t 68k..just changed the oil full synhetic 5-40 "i belive so"...but ever since i bought the car oil pressure light came on...i noticed that when i am in 2 1/2 rpms and lower thats when it turns on...but when im higher then them it doesnt turn on..engine doesnt knockk..first i thought to change the oil "that didnt help" then thought to change sensor "still no do" now the undercarge oil pan is taken apart...oil pan is shiny no sludge what so ever..oil pump seems to be working fine the screen inside the oil pan isnt blocked by anything very clean engine. Any ideas right now its in pieces..i would really appreciate if some on anwsers...thanks and god bless

 

Id try hooking up a mechanical gauge and see what your oil pressure is looking like, maybe the pump isnt running very well... I dont know of many other places oil is know to clog except the pickup tube.