What Causes the Engine Oil Warning Light to Flash During Emergency Braking?
4 Answers
When the engine is running, the oil pressure is generally maintained within the range of 150-350 kPa. If the oil pressure is too low or too high, the oil indicator light on the dashboard will illuminate. The reasons for the oil light flashing are as follows: 1. Excessive oil viscosity. The viscosity of the oil is closely related to its quality. Higher viscosity means better resistance to high temperatures, and vice versa. However, higher viscosity is not always better; the oil grade should match the engine. 2. Pressure relief valve blockage or improper adjustment. 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 in the main oil passage or oil pump. Its function is to limit the oil pressure in the lubrication system to within the specified range. A faulty pressure relief valve can lead to abnormal oil pressure, causing the oil light to illuminate. 3. Insufficient oil level. If the oil level is too low, the oil pump's output decreases or fails to pump oil due to air intake, resulting in reduced oil pressure. This can accelerate wear on the crankshaft, bearings, cylinder liners, and pistons due to inadequate lubrication. 4. Engine overheating. Excessive scale in the 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 leaks through gaps and a drop in pressure, triggering the oil warning light. 5. Clogged oil filter. When the oil filter is blocked and oil cannot pass through, the bypass valve on its base opens, allowing oil to enter the main oil passage unfiltered. If the bypass valve's opening pressure is set too high or too low, the oil pump's pressure will fluctuate, which can also cause the warning light to illuminate. Solution: After the vehicle is powered on, it undergoes a self-check, during which the oil warning light may illuminate. However, if the self-check system detects normal oil pressure within 10 seconds of starting the vehicle, the warning light will automatically turn off—this is normal. If the oil light flashes while driving, it indicates an oil-related issue, and the vehicle should be stopped for inspection or taken to a 4S shop for servicing.
The main reason for the oil light flashing during emergency braking is that the vehicle decelerates rapidly during braking, causing the engine oil to be thrown backward by inertia, temporarily reducing the amount of oil at the oil pump suction port. This leads to a sudden drop in oil pressure, triggering the dashboard warning light. If this happens frequently, it may also be accompanied by issues such as insufficient oil level, oil pump wear, or filter clogging. When dealing with such faults, I always remind my friends: Don't panic. First, safely park the car and check the oil level on the dipstick. If it's too low, top it up with the same type of oil. If the oil level is normal but the light still flashes, it's necessary to visit a repair shop to test the pressure sensor or the pump's circuit. Delaying this could lead to engine damage.
I've been driving for many years and have encountered situations where the oil light flickers during sudden braking. Back then, it was because the car was old, and the oil pump couldn't suck oil fast enough. When the braking force was a bit stronger, the pump inlet couldn't draw oil, causing the light to come on, which was quite frightening. Generally speaking, common causes include insufficient oil, a dirty oil filter, or an aging pressure switch. If you encounter this, I suggest avoiding sudden acceleration and pulling over to check the dipstick first. If the oil level is below the mark, quickly buy a new bottle of oil and top it up. It's good practice to develop a habit of checking the oil level monthly to prevent many potential issues.
The flashing engine oil light during emergency braking usually indicates a momentary drop in oil pressure. Possible causes include: violent deceleration causing oil pan movement and pump suction difficulty, low oil level, sensor malfunction, or poor electrical contact. Pull over immediately for safety first, check and top up oil level or seek professional repair.
