What happens if car engine oil is not changed for a long time?

[VonJudah]

Here are the symptoms of not changing car engine oil for a long time: 1. Prolonged failure to change oil will cause oil deterioration and reduced lubrication effect. When the engine is working, internal components cannot be lubricated, leading to wear of engine internal parts and shortening the engine's service life. 2. For models using engine turbocharging technology, when the turbocharging components start working, the engine torque increases significantly. At this time, the oil film covering the engine crankshaft has to withstand several times higher shear force than before. 3. When engine oil is exposed to high temperatures for a long time, the oil quality will deteriorate after a certain period. Continued use will result in reduced engine power, increased fuel consumption, and most importantly, damage to internal engine components.

[VanSara]

I've been driving for decades and have truly experienced the consequences of not changing the engine oil for a long time. That time I tried to save money by delaying the oil change for over a month, and the oil turned as black as kerosene. The engine noise increased and there was noticeable vibration. Upon inspection, it turned out the oil had oxidized and thickened, losing its lubricating properties. Metal parts were rubbing directly against each other, causing severe wear. In the end, I had to spend thousands on a major engine overhaul. Remember, not changing the oil leads to sludge buildup, clogging the oil filter and passages, reducing cooling efficiency. The engine may overheat and potentially be ruined. I recommend changing the oil at least every 5,000 kilometers or every six months—don't risk major damage to save small change. An oil change only costs a few hundred, while engine repairs can cost double or more. Especially for older cars, be more diligent—safety comes first.

[VonCalvin]

As a young man, I used to be too lazy and forgot to change the oil even after driving my new car for tens of thousands of kilometers. As a result, the fuel consumption inexplicably increased, the car whined when climbing hills, and the power was as weak as if it hadn't eaten enough. It turned out that the old oil had accumulated dirt, greatly reducing its lubricating effect, causing rust and wear inside the engine, and in the long run, it also increased environmental pollution. Later, I set a phone reminder to change the oil on time, and the car immediately ran smoothly. Don't follow my example—engine oil is like the blood of a car and needs to be refreshed regularly. If you don't change it, the engine's lifespan shortens, repairs become more expensive, and it affects the driving experience. Modern cars have maintenance light reminders, so be sure to follow them.

[Valerie]

As a car enthusiast, I deeply understand that engine oil is the guardian angel of the engine. If not changed for a long time, the degraded oil not only provides insufficient lubrication but also fails to clean metal debris. Impurities settle and clog the oil passages or filters, leading to increased engine friction, rising noise levels, higher fuel consumption, and abnormal temperature elevation. In severe cases, piston seizure can occur, resulting in complete engine failure. I once tested this with a modified car – after oil deterioration, acceleration became sluggish, response lagged, and power was noticeably lost. I recommend car owners monitor oil level and color, and change it promptly. Choosing high-quality oil can resist aging and extend protection duration – don’t let your beloved car suffer.