What are the effects of changing engine oil late?
3 Answers
Changing the engine oil slightly late has little impact on the vehicle. However, changing the oil too late can have the following effects on the car: 1. Affect the normal operation of the engine. 2. The car may experience abnormal engine noises. 3. The engine temperature may become too high. 4. The car may experience weak acceleration. Here is a detailed introduction to car engine oil: 1. Engine oil has lubrication, cooling, and cleaning capabilities. It lubricates various components inside the car engine, improving their working compatibility. 2. Engine oil also has a cooling function for the engine, preventing malfunctions caused by excessive engine temperature after prolonged use. 3. Engine oil also cleans impurities such as iron filings inside the engine, preventing blockages that could affect normal engine operation. 4. The engine oil should be changed every 5,000 kilometers. 5. When changing the engine oil, it is best to use the same brand and specification as the original oil. Mixing different brands or grades of oil can affect its normal performance. 6. Engine oil is generally categorized into mineral oil, semi-synthetic oil, and full synthetic oil. Care should be taken to distinguish between them when adding.
I've been driving for over ten years, and delaying maintenance is really no good. Last month, I went over 8,000 kilometers before changing the oil, and the engine made rattling noises during cold starts, with weak acceleration after warming up. Later, inspection revealed sludge had caked up the entire engine interior, costing over a thousand to clean. A friend's car was worse—due to long-term oil degradation, it suffered cylinder scoring and bearing seizure, leading to a major repair costing over seven thousand. Degraded oil loses its lubricating properties, causing metal parts to grind dry and produce debris that clogs the oil filtration system. Now, I go for maintenance 500 kilometers early. After all, a new car running 100,000 kilometers without major repairs relies on timely oil changes—don’t make the same lazy mistake I did.
With over a decade in the auto repair industry, I've seen countless cases of delayed oil changes. Expired engine oil accelerates oxidation, its viscosity dropping to water-like thinness. At this stage, the friction coefficient between piston rings and cylinder walls surges dramatically, causing abnormal wear on crankshaft bearings, while sludge deposits in the oil pan clog oil passages. The most severe cases involve turbocharged models – delayed oil changes lead to coking and seizure of floating bearings, requiring turbocharger replacement costing 7,000-8,000 RMB. Mineral oils must be changed every 5,000 km without exception, and even full synthetic oils shouldn't exceed 12,000 km. Regularly maintained engines can easily surpass 300,000 km, whereas penny-pinching on maintenance often leads to major losses.
