What causes the engine oil warning light to occasionally flash?
2 Answers
The engine oil warning light occasionally flashing may be due to the following reasons: 1. Excessive oil viscosity or overly high oil resistance to high temperatures: Oil viscosity is related to oil quality. The higher the viscosity, the stronger the oil's resistance to high temperatures. However, higher viscosity is not always better. The oil grade should match the engine specifications. 2. Clogged pressure relief valve leading to abnormal oil pressure: To prevent excessive oil pressure in the lubrication system, which increases engine power consumption and causes oil leaks at sealed connections, a pressure relief valve is installed on the main oil passage or oil pump. Its function is to limit the lubrication system's oil pressure to within the specified range. A faulty pressure relief valve can cause abnormal oil pressure, triggering the oil warning light. 3. Insufficient oil volume, reducing oil pressure: This decreases the oil pump's output, lowering oil pressure. The crankshaft and bearings, as well as the cylinder liners and pistons, may experience increased wear due to poor lubrication. 4. Overheating engine accelerating oil aging and thinning, leading to leakage through gaps: Excessive scale in the engine cooling system, poor heat dissipation, prolonged overload operation, or delayed fuel injection timing can cause the engine to overheat. This accelerates oil aging, degradation, and thinning, leading to leakage through gaps, pressure drops, and illumination of the oil warning light. 5. Clogged oil filter causing the bypass valve to open, allowing unfiltered oil into the main oil passage: When the oil filter is clogged and oil cannot flow through, the bypass valve on its base opens, allowing unfiltered oil to enter the main oil passage. If the bypass valve's opening pressure is set too high or too low, the oil pump pressure may rise or fall, triggering the warning light.
A while ago, the oil light in my car occasionally flickered, which gave me a scare. I asked a friend who runs an auto repair shop, and he said the most common cause is low oil level—especially in older cars or those with oil leaks. Insufficient oil can make the oil pressure sensor trigger sensitive alarms. Another possibility is that the sensor itself is dirty or loose, which might cause the light to flicker on bumpy roads. If the oil filter is clogged or the oil pump has minor issues, oil pressure fluctuations can also cause the light to flash momentarily. If the light flickers occasionally, I need to immediately check the dipstick to ensure the oil level is above the midpoint. Don’t delay—low oil pressure can damage the engine. If the light stays on continuously, it’s best to seek professional diagnosis, as safe driving comes first. It’s recommended to check the oil condition monthly as a good habit to prevent potential issues.
