Nissan Repair: oil consumption, oil pressure switch, nissan sentra

Question
99 Nissan Sentra. Back of car Black and oily.  No smoke.  Runs good.  Plugs burning clean.  Empty on oil every couple days.  Now using 20W50 which helps some.  What could it be?

Answer
Hi Larry -

The most common fault is the oil sending unit, or oil pressure switch. This is attached to the engine in the back area, and has one or two wires attached to it. Usually can be removed using a large socket.

Other than that, could be the valve cover gaskets, timing seal, or main seal, but check the above first, and let me know -

hope this helps -
aloha
calvin