When I got my 850 Spider, it leaked lots of oil. LOTS! So far I have replaced the valve cover gasket, fuel pump gasket, oil pan gasket, and front main seal. The engine is now mostly dry but wet around the oil pressure sending unit and on the heat shield over the muffler. Is the sending unit a likely culprit? Do I need to replace the unit or is there a gasket involved. It seems to read just fine. Thanks.