What are the causes of insufficient engine oil pressure?

[VonAriel]

Reasons for insufficient engine oil pressure: 1. The engine oil storage is too low, resulting in low oil pressure; 2. The oil is dirty or viscous, causing the oil pump to fail to suck in or pump out oil, leading to low or no oil pressure; 3. The oil becomes too thin and leaks from the gaps between the engine's friction pairs, resulting in low oil pressure; 4. Faulty oil sensor, pressure gauge, or circuit issues causing low oil pressure; 5. Oil pipe leakage, damaged oil pump, or excessive wear of its components, such as excessive clearance between the crankshaft and bearings, malfunction of the pressure relief valve due to weak springs or damaged steel balls, all of which reduce the oil intake and output, leading to low or no oil pressure.