If your vehicle is showing oil pressure warning light comes on, here are the most likely causes and the parts you'll need to fix each one.
The engine is simply low on oil due to burning, an external leak, or being under-filled during a recent oil change. When the level drops too low, the pump sucks air, causing a sudden drop in pressure.
The sensor that measures oil pressure has failed internally or its wiring is damaged, sending a false low-pressure signal to the dashboard. This is a very common electrical failure that mimics a catastrophic mechanical issue.
An excessively dirty oil filter or the wrong filter installed during a recent oil change can restrict oil flow. If the filter's internal bypass valve fails, oil pressure will drop significantly.
A lack of regular oil changes causes thick sludge to build up in the oil pan. This sludge clogs the screen on the oil pickup tube, starving the engine of oil and dropping pressure.
The mechanical pump responsible for circulating oil has worn out or its internal pressure relief valve is stuck open. This prevents the engine from generating sufficient oil pressure to lubricate moving parts.
Severe internal engine wear at the main or rod bearings creates excessive clearances. This allows oil pressure to bleed off faster than the pump can supply it, usually accompanied by a deep engine knocking sound.