Does Engine Flush Oil Damage the Engine?
3 Answers
Engine flush oil can damage the engine, and the effects of long-term use of engine flush oil include: 1. Causing damage to the internal seals and cylinder block of the engine; 2. Affecting the balance of the oil composition, leading to degraded oil performance. The functions of engine flush oil are: 1. Efficiently cleaning carbon deposits, gum, and other harmful substances inside the engine; 2. Neutralizing long-term harmful acidic substances generated inside the engine; 3. Cleaning the crankcase PVC valve; 4. Preventing the mixing of new and old oil, removing sludge and oil film formed by old oil to avoid reducing the performance of new oil; 5. Cleaning the valve tappets and hydraulic lifters.
Every time I see discussions about engine flush oils, I'm reminded of what happened last year. I was driving an old car at the time and thought cleaning out the carbon deposits might save me some fuel costs, so I bought a bottle of flush oil and poured it in myself. At first, nothing seemed wrong, but after a few days of driving, the engine started shaking badly. A check-up revealed that the flush had loosened years of sludge, partially clogging the oil passages and causing component wear. It cost me several hundred to fix, and I deeply regretted it. In reality, flush oils are designed to remove dirt and clean—good products used correctly are fine. However, if the engine has heavy carbon buildup or if low-quality cleaners are used, problems can arise. My advice: for new cars or those with regular maintenance, flushing might be beneficial without harm; for old or high-mileage vehicles, especially those with frequent idling, it's best not to use them casually unless professionally diagnosed. Now, I stick to regular oil changes with quality oil—prevention is better than repair, and safety comes first.
As someone who loves delving into car knowledge, I've researched extensively and found that engine flush oil itself doesn't directly harm the engine—the key lies in proper usage. If you choose reputable brand products, pour it in before an oil change, let the engine idle for a few minutes, then thoroughly drain it before adding fresh oil, this can clean sludge and improve performance without major issues. Conversely, using the wrong type of cleaner, excessive amounts, or failing to rinse thoroughly may cause dislodged carbon deposits to enter sensitive areas, increasing wear and leading to noise or vibrations. Newer cars tolerate flushes better, while older vehicles, especially those over 15 years, require caution to avoid multiple uses that could corrode components. I've also noticed that short trips immediately after flushing, without allowing the cleaner to fully drain, increases risks. Overall, the benefits outweigh the drawbacks, but don't rely on it as routine maintenance—regular oil changes are the true golden rule.
