How Often Should Internal Engine Cleaning Be Performed?

[Katelyn]

Engine internal cleaning is generally recommended every six months. Below is relevant information about internal cleaning: Drip Bottle Cleaning Method: Currently, the engine cleaning method adopted by 4S shops is commonly known as the "drip bottle" non-disassembly approach. During cleaning, you only need to inject the cleaning agent into the engine and then use a circulation machine to remove carbon deposits and other debris. This method not only effectively eliminates gum, sludge, deposits, and other contaminants inside the engine but also thoroughly cleans the components of the engine lubrication system, preventing damage from acidic substances and metal shavings. Most importantly, it ensures the optimal performance of the lubricating oil and reduces secondary contamination of new lubricating oil. This is because the engine operates in a high-temperature and high-pressure environment, where engine oil and gasoline inevitably generate carbon deposits and gum over time. Prolonged accumulation of these harmful substances can impair oil fluidity and engine combustion conditions, accelerating engine wear. Generally, engine internal cleaning should be performed every 20,000 kilometers as follows: You can use an engine cleaning agent by pouring it into the oil filler port, running the engine for about 5 minutes, and then draining the oil. If the engine is particularly dirty, first drain the oil, add diesel fuel, disconnect the high-voltage line, and use the starter motor to circulate the mixture for about 2 minutes (avoid exceeding this time to prevent damage to the engine oil seals). Alternatively, you can visit an auto detailing shop for professional cleaning, though labor costs may be higher.

[MacChloe]

Having driven for twenty years, I can say an engine is like human blood vessels - accumulated grime will definitely cause problems. Older cars are more prone to sludge buildup, so I recommend cleaning every 80,000 kilometers; for newer cars, waiting until 100,000 kilometers is fine. I remember my 2008 Passat - last year's cleaning flushed out half a teacup of black residue. The key factor is driving conditions: frequent off-road trips or long-term short-distance low-speed driving require more frequent cleanings. The procedure is simple: just pour in a bottle of cleaner during maintenance, let it idle for 20 minutes, and it's most cost-effective to do it synchronously with an oil change. After cleaning, you'll noticeably feel the throttle respond more briskly, and fuel consumption can drop by about 0.5 liters.

[VanAbel]

Just had my little Fit serviced last week, and the technician said engine cleaning doesn't need to be done too frequently. According to the maintenance manual, doing it once every 4 years or 60,000 km under normal driving conditions is sufficient. In fact, for the first three years of a new car, you don't need to worry about this at all unless you're driving on construction sites every day. I've compared the results: the waste fluid at 50,000 km is light brown, while at 100,000 km it looks like sesame paste. One thing to note is that there are two types of cleaners: one for the fuel system and one for the water circulation system. Don't be fooled into doing both; usually, cleaning the lubrication system is enough. The dealership quoted 380 yuan, while a quick repair shop outside charges 200 yuan.

[MacAthena]

Last year at the auto show, an engineer mentioned that modern engines are far more precise than they were two decades ago. As long as you change the full synthetic oil on schedule, there's basically no need for specialized cleaning within 120,000 kilometers. Our fleet of 50 vehicles was tested, and when the engines were disassembled at 100,000 kilometers, the cylinder blocks using genuine oil still had a metallic shine. In contrast, vehicles that frequently missed oil changes already had noticeable sludge buildup by 30,000 kilometers. If you really want to maintain your engine, the most cost-effective method is to add a can of cleaner before each oil change and drive about 50 kilometers. Don't fall for those deep disassembly cleaning services—over-tightening screws can actually lead to oil leaks.