How to Check Engine Oil Quality?
3 Answers
Methods to check engine oil quality: 1. Color Identification Method: Take a small amount of oil in a transparent container. Normal oil appears brown or blue-black. A milky yellow color indicates the oil is mixed with diesel or water and should be replaced immediately. A deep black color means the oil has deteriorated and must be changed. 2. Oil Spot Method: Stir the oil to be checked and drop it on white paper. The oil spot will spread outward from the center, forming three concentric circles. The condition of the oil can be determined by the color, width, and shape of these three areas. 3. Rubbing Method: Take a small amount of oil from the oil pan, apply it to your fingers, and rub between your thumb and fingers. If you feel impurities in the oil, a lack of viscosity like water, or even a rough or sour smell, it indicates the oil has deteriorated. If you see tiny shiny metal particles on your fingers after rubbing, it means there is significant wear in the engine and the oil must be replaced immediately.
I learned to check oil quality through driving experience. First, park the car on level ground, wait 3-5 minutes after turning off the engine to let the oil flow back to the oil pan. Then pull out the engine dipstick, wipe off the old oil with a clean cloth, reinsert it fully and pull it out again. Now observe the oil level—it should be between the high and low marks on the dipstick. Color is key: fresh oil is clear and golden; if it's black or dark, it may be severely oxidized and due for a change. I dip my finger in the oil and rub it—moderate viscosity is ideal. Too thin may indicate dilution, too thick means excessive resistance. Give it a sniff: a gasoline or burnt smell indicates contamination. I also recommend monthly checks—don’t wait for the dashboard warning light. Regular oil changes extend engine life and prevent breakdowns. By the way, if you often drive long distances, check it at gas stations—simple and safe. Don’t overlook this small task.
Checking engine oil is my expertise, having driven trucks for over 100,000 kilometers. First, park the vehicle on level ground and wait for the engine to cool down. Pull out the dipstick, wipe it clean, reinsert it, then pull it out again to check if the oil level is within the marked range. The oil film should be uniform and translucent; if it appears layered or cloudy, it's likely deteriorated. Test the oil quality with your fingers: drop a bit between your thumb and forefinger and stretch it. If it breaks easily, it's too thin; if it's too sticky to stretch, there's a problem. Don't ignore the smell—it should be odorless. I change the oil every 5,000 kilometers to save money and prevent major repairs. If the engine noise increases or fuel consumption rises while driving, it might be due to poor oil quality. Choose the right oil grade when changing: thicker in summer and thinner in winter to match the weather and avoid engine overheating. Simple maintenance keeps the engine running smoothly.
