The oil pressure switch determines the oil pressure in the engine and sends that information to the driver through the gauge cluster. When a sudden loss in oil pressure is detected, a light goes off, and you should immediately turn off the vehicle. If the sensor seems to be malfunctioning, then replacing it is important so you don't risk damaging the engine. In this case, the project vehicle is a 1998 Oldsmobile Cutlass with the 3.1-liter engine, but the process is similar for other models, as well.
Use the jack to lift up the front of the vehicle, then set it on the jack stands. Be sure that the vehicle is completely and solidly on the stands prior to working on the vehicle.
Shine the flashlight underneath the engine and locate the oil pressure switch just behind the starter on the engine. This is between the starter and the oil filter, mounted on the engine block. Unplug the wiring harness, connecting it to the vehicle.
Unbolt the switch from the engine block using the 3/8-inch ratchet and deep-well sockets.
