Is Coolant Entering the Cylinder a Serious Issue?

[Joanne]

Coolant entering the cylinder is a relatively serious issue. When coolant leaks into the engine's cylinder block, it can cause the engine oil to turn milky white. Coolant entering the cylinder is typically due to a faulty cylinder head gasket, which compromises the sealing performance. The cylinder head gasket must be replaced to prevent further engine operation issues. The functions of coolant include the following: 1. Cooling Effect: Cooling is the fundamental role of coolant. During engine operation, a significant amount of heat is generated, with approximately 60% dissipated through the cooling system. Water and methanol-based coolants have low boiling points and are prone to boiling. If the vehicle operates under such conditions, even briefly, it can lead to engine damage. 2. Anti-Corrosion Effect: The cooling system consists of components like radiators, water pumps, cylinder blocks, cylinder heads, and water distribution pipes, made from metals such as steel, cast iron, brass, copper, aluminum, and solder. Due to varying electrode potentials among these metals, electrochemical corrosion can occur in the presence of electrolytes. Additionally, acidic byproducts from decomposed glycol in the coolant and acidic exhaust gases from fuel combustion may infiltrate the cooling system, accelerating corrosion. 3. Anti-Scale Effect: Scale in the cooling system originates from cations like calcium and magnesium in water. Under thermal load, these alkaline earth metal cations react with anions in water to form scale. Scale can wear out water pump seals and coat the outer walls of cylinder block water jackets, reducing thermal conductivity and causing localized overheating in cylinder heads, potentially leading to cracks. To minimize scale formation, deionized water treated through softening processes is used during coolant production and refilling. 4. Anti-Freeze Effect: In winter, low temperatures necessitate the addition of antifreeze agents to engine coolant to lower the freezing point of water, ensuring the cooling system remains functional in cold weather without freezing. 5. Heat Dissipation Effect: Coolant provides efficient heat dissipation, removing excess thermal energy from the engine to regulate the temperature of critical metal components.