Oil Pressure Sensor/Switch - 1991 300ZX Z32

The oil pressure sensor on the 1991 Nissan 300ZX VG30DETT monitors lubrication system health for the analog dash gauge. Located on the oil filter cooler block, this single-wire sender uses Nissan part numbers 25240-89915 (superseded by 25240-8991A). Interchange spans all 1990-1996 Z32 chassis, including VG30DE naturally aspirated engines—junkyard hunters should prioritize abundant NA donors for identical fitment. When inspecting used units, check for oil weeping at the metal-to-plastic crimp joint and green corrosion on the bullet connector. Installation requires 1/8" BSPT thread sealant applied sparingly to prevent port contamination; torque to 15 Nm to avoid cracking the ceramic element. Common failures include internal diaphragm leaks causing low gauge readings and shorted windings pegging the needle at max. Always verify the single-blade electrical connector matches your harness, as the adjacent oil temperature sensor on turbo models uses a different plug. Test resistance across the terminal and body: values should decrease smoothly with increasing pressure.