How much can the engine oil exceed the upper limit without causing issues?
2 Answers
Engine oil exceeding the upper limit by 1 centimeter is acceptable. When the engine is cold, the oil level can be 1 centimeter above the upper limit, and when the engine is hot, it should be right at the upper limit. When the engine is cold, all the oil adhering to the cylinders, crankshaft gears, etc., flows back into the oil pan. When the engine is hot, much of the oil is distributed across various lubrication surfaces, so the level will be slightly lower. Engine oil is the lubricant used in engines, serving functions such as lubrication and wear reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, and shock absorption. Base oil is the main component of lubricants, determining their fundamental properties, while additives can compensate for and improve any deficiencies in the base oil's performance, providing certain new capabilities.
How much above the oil level limit is acceptable? Exceeding the limit by about 10mm is usually fine, but it's best not to go beyond that point. Too much oil increases internal engine pressure, which can cause oil foaming and reduce lubrication effectiveness, potentially accelerating engine wear. Prolonged overfilling may damage valve seals or lead to oil leaks—I've encountered similar issues before, where the car developed unusual noises. When checking oil levels, warm up the engine first, then wait ten minutes after turning it off before measuring with the dipstick for accuracy. If the oil level is too high, carefully remove some using an oil extraction tool to maintain the mid-level mark. Regular maintenance is crucial—when changing oil, avoid overfilling and remind mechanics to follow standard quantities. Routine checks should include monitoring oil color; replace it early if it appears black. These small habits can extend your car's lifespan and ensure smoother driving.
