What are the symptoms of not changing engine oil for a long time?
2 Answers
Symptoms of not changing engine oil for a long time are as follows: 1. Reduced sealing effect: High-quality engine oil with appropriate viscosity can effectively seal the gap between the cylinder block and piston, preventing gas leakage. If the oil is not changed for a long time, it will become watery and lose its sealing function. 2. Reduced cooling effect: The heat absorption and conduction properties of oil are far superior to water. If the oil deteriorates severely, its cooling function will be greatly reduced. 3. Reduced lubrication effect: The viscosity of engine oil gives it strong adhesion, allowing it to form a protective film between gears, shafts, and other components, ensuring smooth operation and reducing wear. Deteriorated oil largely loses this function.
Not changing engine oil for a long time, as a veteran driver with over a decade of experience, I've seen many friends neglect this. At first, the car will develop louder engine noise, buzzing incessantly, sounding like it's protesting. Fuel consumption also rises sharply—previously a full tank could cover 500 kilometers, but now it might only reach 450, and the car feels sluggish with delayed acceleration. What worries me most is blue or black smoke from the exhaust, indicating degraded oil causing poor lubrication and internal engine friction. Once, my car had difficulty starting, stuttering a few times when cold before firing up—later inspection revealed the oil had thickened like glue, nearly causing engine seizure. Long-term neglect leads to sludge buildup clogging oil passages, not just increasing fuel consumption but also causing engine overheating or even total failure. That's why I stick to changing oil every 8,000 km or 6 months, ensuring proper lubrication to avoid costly overhauls and drive with peace of mind.
