Oil Pressure Gauge

The oil pressure gauge is mounted on the instrument panel of a vehicle. Marked off on a dial in pounds per square inch (psi), the gauge indicates how regularly and evenly the oil is being delivered to all vital parts of the engine and warns of any stoppages in this delivery. Pressure gauges may be electrical or mechanical.

In the mechanical type, the gauge on the instrument panel is connected to an oil line tapped into an oil gallery leading from the pump. The pressure of the oil in the system acts on a diaphragm within the gauge, causing the needle to register on the dial.

In the electrical type, oil pressure operates a rheostat connected to the engine that signals electrically to the pressure gauge indicating oil pressure within the system.