On the instrument panel, if the oil pressure gauge shows an abnormally low pressure with no apparent fault in the circuit, what is the usual condition of the engine oil?

Question

DentroTest · Accepted Answer

The viscosity of lubricating oil decreases in proportion to the rise in its temperature. If the engine or the oil reaches an excessively high temperature, the lubricant loses density and becomes noticeably more fluid. This loss of viscosity makes the resistance to the flow of the fluid through the engine's passages lower, which translates immediately into a drop in the pressure shown on the gauge, even when the pump and the rest of the lubrication circuit work correctly. By contrast, when the oil is cold or warm, it keeps a higher viscosity, which produces normal or even high pressure in the circuit.

On the instrument panel, if the oil pressure gauge shows an abnormally low pressure with no apparent fault in the circuit, what is the usual condition of the engine oil?

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