What are the effects of overfilling engine oil during car maintenance?
3 Answers
Overfilling engine oil during car maintenance can have several effects: 1. It increases fuel consumption and affects engine power. When too much oil is added, the oil level becomes too high, causing a significant portion of the crankshaft to be submerged in the oil. This creates resistance when the crankshaft rotates, greatly increasing rotational drag. 2. It accelerates the formation of carbon deposits and damages certain car components. As the crankshaft churns the oil, a large amount of oil is splashed onto the pistons and cylinder walls, entering the combustion chamber and burning. Carbon deposits have long-term effects on engine power and fuel consumption. 3. It can cause oil leakage from the crankshaft oil seal and shorten the oil's shelf life. The excessive churning of oil increases pressure inside the crankcase, which acts on the crankshaft oil seal, accelerating its aging and deformation, ultimately leading to oil leakage. It also speeds up the oxidation and deterioration of the oil, reducing its shelf life. 4. It worsens exhaust emissions, severely affecting the lifespan of the catalytic converter and potentially causing direct damage to it.
I had trouble when I overfilled the engine oil during my last car maintenance. The engine sounded unusually loud when driving, with poor acceleration, and fuel consumption suddenly jumped from the usual 8 liters to 11 liters. Even worse, blue smoke came out from the exhaust. After inspection, I found that the excess oil caused the crankshaft to stir too much, creating foam and causing oil pressure to spike. This led to oil seals starting to leak, reducing lubrication effectiveness. Over time, the oil could also seep into the combustion chamber, causing incomplete combustion and damaging the catalytic converter—repairing just the catalytic converter cost me several thousand yuan. I learned my lesson: now I always carefully measure the oil level with the dipstick to ensure it stays between the min and max marks. If I accidentally overfill, I use a suction tube to remove the excess to prevent further damage. Safety comes first—regularly checking the oil level is essential, and don’t wait until problems get worse to take action.
As a car enthusiast, I've experienced the drawbacks of overfilling engine oil. The performance was noticeably sluggish. Excess oil caused the crankshaft to dip too deep, consuming extra power during rotation and making the engine response sluggish, like wearing lead shoes during acceleration. Meanwhile, foamy oil reduced lubrication, accelerating component wear; increased fuel consumption also led to blue smoke from the exhaust pipe, and if combustion was incomplete, spark plugs would get dirty easily. The worst part was catalytic converter damage—I've faced skyrocketing repair costs. So now, I strictly control the oil amount during changes and use a dipstick to check precisely. Performance cars are especially sensitive—too much oil directly ruins the dynamic rhythm. Developing good habits makes vehicle maintenance much easier.
