Why is there engine oil in the radiator?
2 Answers
Here are the reasons for engine oil entering the radiator: 1. Cylinder liner damage. The presence of engine oil in the radiator may be due to cracks in the cylinder liner. Under high pressure, engine oil can seep directly into the car radiator through these gaps. 2. Radiator damage. Additionally, damage to the engine oil radiator or transmission radiator can also cause oil to mix into the radiator, so it's necessary to inspect these components. 3. Cylinder head gasket damage. If there is engine oil in the radiator and the high-temperature warning light is on, it may be due to a damaged cylinder head gasket. Since the fuel in the cylinder is under high pressure for a long time, leading to cylinder liner damage, the oil and water passages can become interconnected. In summary, there are many factors that can cause engine oil to enter the radiator. If any damage is found, simply replacing the affected part with a new one should resolve the issue.
Oil in the radiator is no small matter. My car had this issue before, and it was downright nerve-wracking. The main cause is usually a failed engine head gasket, which acts like a sealing wall separating the oil and coolant passages. When it wears out or deforms due to high temperatures, oil can leak into the cooling system. Other possible causes include cracked oil cooler pipes or tiny fractures in the engine block. The consequences are serious—oil contamination can clog water pipes and the radiator, leading to poor engine cooling, overheating, or even complete engine failure. While driving, you might notice a sudden temperature spike, reduced power, or white smoke from the radiator. Stop the car and turn off the engine immediately—continuing to drive increases the risks. Take it to a reliable repair shop for inspection; you may need a new head gasket and a full cooling system flush, costing anywhere from a few hundred to over a thousand dollars. During regular maintenance, keep an eye on the head gasket’s condition and any changes in coolant color to prevent similar failures.
