Why does the oil light come on when parked but not when driving?
3 Answers
When idling while parked, the oil pressure may be low. During driving, the engine speed is higher. It is recommended to check as soon as possible whether the low oil pressure is caused by an issue with the oil pump or excessive bearing clearance. The reasons for the car oil light coming on are as follows: 1. Excessive oil viscosity: The viscosity of the oil is closely related to its quality. The higher the viscosity, the better the oil's resistance to high temperatures, and vice versa. However, higher viscosity is not always better; the oil grade should match the engine specifications. 2. Pressure relief valve clogged or improperly adjusted: To prevent excessive oil pressure in the lubrication system, which increases engine power consumption and causes leaks at sealed connections in the oil circuit, a pressure relief valve is installed in the main oil passage or oil pump. Its function is to limit the oil pressure in the lubrication system to within the specified value. A faulty pressure relief valve can lead to abnormal oil pressure, causing the oil light to illuminate.
My car's oil light comes on when I stop, but turns off when I drive, which is really unsettling. The reason could be that the oil level is too low. When parked, the oil sits still in the oil pan, and the sensor detects insufficient pressure, triggering the light. When driving, the oil pump draws oil, increasing the pressure and turning the light off. Another possibility is that the oil pump is aging and can't supply enough pressure at idle, but compensates when the engine speed increases. It could also be a faulty oil pressure sensor or poor wiring contact, sending false signals. Here's what you can do: After parking and turning off the engine for ten minutes, pull out the dipstick, wipe it clean, reinsert it, and check the oil level. If it's below the mark, add oil that meets the required standards. If the level is normal but the light still comes on, take it to a repair shop to check the pump or sensor. Don't delay—low oil levels accelerate engine wear, leading to more expensive repairs. Safety first—take this seriously.
Encountered this issue on my friend's car: the parking light stays on but turns off when driving, mostly due to insufficient oil. Think about it—when parked, oil flows slowly, triggering the warning light for low oil pressure; when driving, the RPM increases, the oil pump works more efficiently, and the light goes off. Additionally, a loose or dirty sensor connector can also send false signals. The solution is simple: first, check the oil level—pull out the dipstick and top it up if it's low; if it's normal, it might be due to a worn oil pump or relay failure. Remember to change the oil regularly to avoid sludge buildup affecting the pump's operation. Once, I delayed it too long, and the engine started making loud noises, costing me thousands in repairs. Don't save small money only to lose big—have a technician check it during quarterly maintenance for peace of mind.
