Is Engine Cleaning Oil Useful?

[TheoMarie]

Yes, engine cleaning oil, also known as engine cleaner, is used to clean the engine. It can remove harmful substances such as sludge, carbon deposits, and gum inside the engine, maintaining internal cleanliness. This enhances oil flow, reduces component wear, and extends the engine's lifespan. 1. Regarding engine carbon deposits and sludge: Engines operating for long periods under high temperatures may accumulate carbon deposits and impurities due to fuel issues. While engine oil has some cleaning effect, it is not very effective at removing carbon deposits. Additionally, engine oil tends to produce sludge over time, which is difficult to clean. Excessive carbon deposits or impurities inside the engine can hinder oil flow and accelerate engine wear. Engine cleaning oil can help remove carbon deposits to some extent. 2. Solutions for excessive carbon deposits and sludge: For vehicles that have never used engine cleaning oil and have high mileage or age, using a cleaner may cause oil passage blockage if there is significant sludge buildup, and the cleaning effect may not be ideal. It is more practical to focus on regular vehicle maintenance, ensure proper upkeep, check engine oil periodically, and use high-quality engine oil.

[AaronFitz]

I've been researching engine maintenance, and whether engine flush is useful depends on how you use it. If your car has run 70,000-80,000 kilometers without ever being cleaned, it's definitely beneficial as it dissolves carbon deposits and sludge, making the engine run smoother. The principle is to add it to the old oil and let it idle, softening and removing the dirt stuck to the parts. But I must warn you, it's completely unnecessary for new cars or those with regular maintenance—it's a waste of money and could even damage the seals. Some repair shops trick you into using it with every oil change, which is just a money grab. Personally, I only consider using it every 50,000 kilometers, and only if the engine is noticeably shaking or fuel consumption has increased. When using it, you must choose a reliable brand, as low-quality flush can corrode metal parts.

[VonDeclan]

I've been repairing cars for over a decade and have seen too many car owners struggle with this. Engine cleaning oil is essentially a powerful detergent, and its effectiveness depends on how dirty the engine is. Cars that frequently drive at low speeds are particularly prone to carbon buildup, and a cleaning can indeed restore power—you'll notice the accelerator feels much lighter. However, if the car is running fine, using it might backfire, as large chunks of sludge dislodged during cleaning can clog oil passages. Just last month, a BMW owner used cleaning oil for the first time at 100,000 kilometers, only to have the oil pump screen clogged, resulting in a major repair costing several thousand. So my advice is to consider it only after 70,000 to 80,000 kilometers, and always do it before an oil change. Don't fall for those so-called 'deep maintenance packages'—they're just a waste of money.

[OAdriel]

A few days ago, I took my old Passat for maintenance, and the mechanic recommended using engine flush oil. He said my car is burning oil and the piston rings have severe carbon buildup. After using it, I felt the idle was smoother, but the effect wasn’t as miraculous as expected. This stuff is essentially a chemical solvent, mainly targeting sludge and carbon deposits, but it doesn’t help with worn parts. If it’s just regular maintenance, sticking to timely full synthetic oil changes makes it unnecessary. However, it’s particularly useful for older cars, especially those frequently driven short distances, as low engine temperatures make carbon buildup more likely. Nowadays, auto repair shops often push this service, but personally, I don’t think it’s necessary to do it every time—once every three to five years is enough. Just remember to buy products from reputable manufacturers, as those from small workshops can corrode rubber components.

[RileyAnn]

Over the years of running my repair shop, I've noticed many misconceptions about engine flush products. They're neither a scam nor a miracle solution – their effectiveness depends entirely on usage scenarios. Vehicles frequently driven in dusty environments genuinely benefit, as engine flush can remove metal particles settled in the oil pan. However, new cars within their first three years rarely need it, as quality engine oil already contains cleaning agents. A crucial reminder: After flushing, ensure complete drainage of all residues. I've witnessed cases where incomplete drainage caused emulsification of fresh oil. These products work better on fuel-injected vehicles than carbureted ones, and are particularly suitable for direct-injection engines prone to carbon buildup. Don't expect them to fix oil burning issues – that indicates mechanical damage. When purchasing, choose reputable brands like Shell or 3M, and avoid cheap alternatives.