What Causes White Oxidation Spots on Engine Blocks?
3 Answers
The reasons for white oxidation spots appearing on engine blocks are as follows: 1. If it's a new imported car, the engine may oxidize. Vehicles shipped from overseas to China are typically transported by sea. The air and seawater at sea contain high salt content, which inevitably adheres to the vehicle during transportation, causing some corrosion and leading to engine oxidation. 2. Spot-like white corrosion is usually aluminum oxide. Many aluminum alloy engine blocks and cylinder heads may corrode over time when exposed to coolant, battery acid, or water. 3. Minor corrosion does not affect engine performance. 4. If the appearance is a concern, the white corrosion can be wiped off after the engine cools down. 5. To prevent future exposure to the aforementioned corrosive substances.
Last time at the repair shop, when I disassembled the engine, I noticed white spots on the cylinder block, which are actually signs of metal oxidation. The most common cause is coolant leakage, such as aging cylinder gaskets or cracks in the cylinder block, allowing liquid to come into contact with the hot metal surface and causing corrosion. Humid environments can also accelerate this issue, especially in coastal areas where the combination of salt and moisture is highly corrosive. These white spots may not seem serious at first, but if left untreated, they can damage the cylinder block's sealing, affect heat dissipation, and even lead to oil burning. The solution involves first locating the leakage point, thoroughly cleaning the corroded surface, and in severe cases, replacing the damaged parts. For regular maintenance, always use genuine antifreeze and never cut corners by mixing it with tap water. It's also crucial to regularly check the cooling system pressure.
My old car developed white spots on the cylinder block last year, which was really worrying. The mechanic said there are mainly two scenarios: first, coolant leakage leaves white mineral deposits after evaporation; second, prolonged exposure to humid air causes erosion, especially for cars parked in garages. Aluminum cylinder blocks are more prone to this electrochemical corrosion. I found that if not treated promptly, the corrosion spots gradually expand and lead to seal failure. It cost me 800 yuan to replace the cylinder head gasket and use specialized cleaning agents to fix it. I suggest avoiding direct water jet cleaning of the engine when washing your car, and always dry it afterward. For those living in coastal or high-humidity areas, using a car cover can help reduce moisture damage.
